ISSSD 2017 Book of Abstracts

ISSSD 2017 XVII INTERNATIONAL SYMPOSIUM ON SOLID STATE DOSIMETRY Host Book of abstracts Santo Domingo, Dominican Republic September 26th to 30th, 2017 ISSSD 2017 Organizing Committee Emma Kareline Encarnación Encarnación President Antonio Almonte, Modesto Sosa Edith Paulino, Juan Azorín Denia Cid, Hector Rene Vega-Carrillo Héctor Lee, Miguel Vallejo Félix Cid, Francisco Medina Leonardo Peguero, Cristian González i ISSSD 2017 International Scientific Committee Hector Rene Vega-Carrillo Chairman Teogenes Augusto da Silva (Brazil), Marco Aurelio de Sousa Lacerda (Brazil) Telma C. Ferreira Fonseca (Brazil), Eduardo Villareal Barajas (Canada) Segundo A Martínez Ovalle (Colombia), Mercedes Díaz Lagos (Colombia) Emma Kareline Encarnación Encarnación (Dominican Republic) Melvin Arias (Dominican Republic), Antonio Almonte (Dominican Republic) Juan Manuel López (Dominican Republic), Pascual Abreu Rijo (Dominican Republic) Ahmed El-Khayatt (Egypt), Vishwananth P Singh (India), Rahim Khabaz (Iran) Claudio Furetta (Italy), Teodoro Rivera Montalvo (Mexico), José Guzmán Mendoza (Mexico) Consuelo Letechipía de León (Mexico), Enrique Gaona (Mexico), Juan Azorin (Mexico) Teodoro Córdova Fraga (Mexico), Miguel A Salas Luevano (Mexico) Jose M Ortiz Rodríguez (Mexico), Erika P Azorin (Mexico), Silvia E Burruel (Mexico) Catalina Cruz (Mexico), Victor R Orante (Mexico), Rodolfo Bernal (Mexico) Modesto Sosa (Mexico), Pablo V Cerón (Mexico), Jorge L Benites Rengifo (Peru/Mexico) Jhonny A Benavente Castillo (Peru), Eduardo Medina (Peru), Eduardo Gallego (Spain) Roberto Méndez (Spain), Karen A Guzmán-García (Spain), Virgilio Correcher (Spain) Ahmed Ben-Ismail (Tunisia), Richard Hugtenburg (UK), David Bradley (UK/Malaysia) Manuel Arreola (USA), Nolan E. Hertel (USA), Laszlo Sajo-Bohus (Venezuela) ii ISSSD 2017 Table of Contents Cerón R., PV et al., Respuesta termoluminiscente del dialuminato de calico intrínseco e impurificado con Cr3+. Orante-Barrón, VR et al., New investigations related with lanthanide-doped magnesium oxide obtained by glycine-based solution combustion synthesis: Exerting influence of addition of Li+ on thermoluminescence properties. Orante-Barrón, VR et al., Novel thermoluminescence features of La2O3 phosphors obtained by an optimized urea-based solution combustion synthesis. Elías Ángel, JA et al., Synthesis and thermoluminescence characterization of lithium borate glasses doped with Dy3+ and Yb3+ and containing silver nanoparticles. Rivera Pérez, E et al., Efecto morfológico y termoluminiscente de LiF puro y dopado con Ce3+ usando surfactants no-iónicos y catiónicos en el proceso de síntesis. Santos Sandrini, E et al., Evaluation of collimator rotation for VMAT lung SBRT using flattening filter free. Avilés-Monreal, R et al., Thermoluminescence properties of new Dy doped ZnO phosphors exposed to beta particle irradiation. Avilés-Monreal, R et al., Effect of thermal annealing on the luminescence properties of Na doped ZnO. Escobar Ochoa, FM et al., Determination of kinetic parameters of thermally stimulated luminescence of magnesium oxide doped with lanthanum and lithium. Santana PC et al., Whole-body 18F-FDG PET-CT scanning with CT for anatomical mapping: Radiation levels for oncologic diagnosis. Sánchez Jáquez, FR & Sosa Aquino, M. Respuesta termoluminiscente del Y2O3:Ce,Eu irradiado con rayos X. Vallejo, MA et al., Síntesis y caracterización termoluminiscente de vidrios de fosfato activado con iones de Dy3+ que contienen nanopartículas de plata. Escalona Llaguno, MI et al., Determinación del K-40 en croquetas. Córdova Fraga, T et al., Nano magnetite recubierta de oro: Terapia oncológica alternative con hipertermia magnética. Soto-Bernal, TG et al., Producción de neutrones en la interacción de electrons con una laminilla dispersora. Mandujano-García CD et al., Análisis de los niveles de radioisótopos en muestras ambientales de Dos Bocas, Tabasco. Olaya Dávila, H et al., Optimization by Monte Carlo method of photon fluence from the Xray beam spectrum in a bimodal tomographic system. Vedelago J et al., Integration of Fricke gel dosimetry with Ag nanoparticles for experimental dose enhancement determination in theranostics. iii 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Peña Vidal, JD et al., Análisis del diseño de un tubo de rayos X utilizando MCNP. Azorín, J et al., Type testing of a locally made LiF:Mg,Ti + PTFE TLD for its use as a personal dosimeter. Baltazar-Raigosa, A et al., Matriz respuesta de volúmenes regulares de moderador con detector de 3He mediante métodos Monte Carlo. Azorín, J., An overview on preparation and characterization of calcium sulfate for thermoluminescence dosimetry (TLD). Alves, N., et al., Thermoluminescent properties of polycrystalline carbon doped LaAlO3/La(OH)3 by solid state reaction for application in UV dosimetry. González, PR et al., Propiedades dosimétricas de -Al2O3:TM+PTFE. Goncalves Leao Junior, R et al., Relevance of the electron source size in simulations of linear accelerators using the Monte Carlo method. Sulieman, A et al., Assessment of effective radiation dose to patients in certain radiographic examination in Alkharj city. Marmolejo-León, P et al., Estimation of the effectiveness ratio () for resistant cancer stem cells in U87MG human glioblastoma. Valente, M et al., Water-equivalence of gel dosimeters for radiology medical imaging. Torres-Hoyos, F et al., Geometric study of Astrocytomas with fractal analysis. Abrao Lima, LT et al., Protocol optimization in chest CT scancs of newborn. Flores Hernández, C. Evaluación del riesgo crónico por uso de radiación en personal ocupacionalmente expuesto (POE) en el area de la salud oral. Bustos Flores, M & Prata Mourao, A. Microcalcification evaluation using CR plates in computerized mammography. Namen Aburjaile, W et al., Comparative dosimetric study using pediatric phantom in chest computed tomography scans. Hernández Rayas, A et al., Diseño y desarrollo de un sistema de localización de vasos sanguíneos mediante visor NIR. Rodríguez Pérez, EX. Pruebas de hipótesis estadísticas en la respuesta de la proliferación de un cultivo de Saccharomyces cerevisiae con variación en los parámetros del campo magnético aplicado. Hernández-Mendoza, H., Análisis de Plutonio-239 en personal ocupacionalmente expuesto. Sosa, MA et al., Presencia de micronucleus en personal medico y asistentes en centros de radiología en México. Speckter, H et al., Inversión recovery sequences improve delination of optic pathways in the proximity of suprasellar lesions. Speckter, H et al., Diffusion tensor imaging parameters predict response of meningiomas to radiosurgery. Coripuna, RL et al., Hipertermia generado por corrientes Foucault para tratamientos oncológicos con COMSOL. Benites-Rengifo, JL & Vega-Carrillo, HR, Determinación de la distribución especial de dosis en tratamientos de CACU con braquiterapia LDR usando métodos Monte Carlo. Alkhorayef, M et al., Staff and ambient radiation dose in therapeutic nuclear medicine procedures. Quispe Huillcara, B. Determinación de la dosis en cristalino y tiroides durante el examen de tomografía de tórax con MCNP. iv 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 Nayl Edam, A et al., Quality control in dual head -cameras: Comparison between methods and softwares used for image analysis. García Durán, A et al., Analizador multicanal embebido en FPGA. Hernández-Mendoza, H et al., Validación de métodos para medir isótopos de Uranio usando espectrometría de masas de sector magnético con fuente de plasma acoplado inductivamente. Cano Sánchez, D et al., Visualización de las partículas cargadas ionizantes. Ramírez-Romero, MI. et al., Caracterización dosimétrica de KMgF3:Tb + PTFE. Hernández-Reyes, B et al., Verificación dosimétrica en radioterapia conformal con un sistema de imagines portales. Méndez, R et al., Experimental evaluation of the 252Cf and 241Am-Be neutron sources of the Neutron Standards Laboratory of CIEMAT (Spain). Guerra Paiva, F. et al., Evaluation of patient absorbed dose in a PET-CT test. Cevallos-Robalino, LE et al., Estudio mediante métodos Monte Carlo de un sistema de detección de explosivos utilizando un generador D-D y detectores de NaI(Tl). Costa, KC et al., Radiochromic film calibration for dosimetry in Computed tomography test. Lopes da Cunha, E et al., Photoluminescence properties of PBAT/Amylum blends applied to radiation dosimetry. Ballon Peralta, CI et al., Optimización del código PENELOPE en lenguaje F# para la simulación del espectro de rayos X en radiodiagnóstico. Werneck Affonso, RR et al., NaI(Tl) detectors modeling in MCNPX and Gate/Geant4 codes. Vega Ramírez, J et al., Caracterización de tejidos equivalents al cuerpo humano mediante el método Monte Carlo para rayos X. Camargo, L et al., Optically stimulated luminescence properties of Tm3+ doped KMgF3 fluoroperovskite. Fernandez, Y et al., Angular characterization of the response of an YVO4:Eu3+-based radioluminescence probe under LINAC irradiation. Figueroa, R et al., X-ray production in different anode geometries: Theoretical and Monte Carlo simulation approaches. Figueroa, R et al., Theory, simulation and experiments for precise deflection control of radiotherapy electron beam. Lopes J et al., Assessment of LabSOCS as a tool for the calculation of self-attenuation coefficients in gamma spectrometry. Pastrana Orejuela, CO et al., Influencia de los rayos X de frenado en la calidad de las imagines SPECT con Itrio-90 utilizando simulación Monte Carlo. Quispe Valeriano, NY et al., Simulación del espectro (Co-60), Theratron Equinox, usando el código PENELOPE v. 2008. Santibáñez, M et al., Determination of the dose enhancement due to Gadolinium using EBT2 and EBT3 gafchromic films irradiated with 192Ir, 241Am, and low-energy X-ray sources. Lemos Thalhofer, J et al., Simulation of lung cancer treatment with equivalent dose calculation and analysis of the dose distribution profile. Encarnación Encarnación, EK et al., Síntesis y caracterización de fluoruro de litio activado con plata. Fontainha, CCP et al., Study of carbon-doped micro and nanosized alumina for radiation dosimetry applications. v 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 Franca, LVS et al., Electron paramagnetic resonance studies of a new luminescent material based on CaB6O10:Pb. Castañeda-Miranda, VH et al., Design of a technological tool for the solution of inverse problems using neural networks of reverse propagation with application to neutron spectrometry. Castañeda-Miranda, VH et al., Automated optimization of neutral networks of reverse propagation using statistical techniques with application to neutron spectrometry. Gortárez, MA et al., Thermoluminescence properties of MgO:Eu,Li obtained by glycinebased solution combustion synthesis. Campos de Oliveira, PM. Quality image and incident air kerma evaluation in X-ray chest exams. Dutra Garcez, RW et al., Determination of Ra-226, Ra-228 and K-40 specific activities in samples of mineral fertilizer used in the Brazilian city of Rio de Janeiro. Gonzales, AL et al., Calculation of dose profiles in cylindrical phantoms of water equivalent materials. Hernández-Mendoza, H et al., Cuantificación de los niveles de Uranio en agua subterranean en el municipio de San Diego de la Unión, México. Gaona, E et al., Exploratory survey of initial image quality in new digital mammography units prior to use in patients in Mexico. Ortiz Allende, MD et al., Medición del coeficiente de atenuación lineal de la cerveza. Ladino Gómez, AM & Prata Mourao, A. Estudio de dosimetría utilizando maniquí de cabeza en exploraciones de tomografía computarizada. Sánchez-Ortega, GE et al., Thermoluminescence properties of magnesium oxide doped with dysprosium and lithium obtained by solution combustion synthesis. Hernández-Pérez, TC et al., Thermoluminescence of Mg doped Li2ZrO3 exposed to beta particles. Rojas Solis, DA. et al., X ray quality control using thermoluminescent dosimeters. Cruz-Zaragoza, E et al., Thermally-and photo-stimulated luminescence of red eggshell irradiated by gamma of Co-60 Ramírez Luna, A & Schaaf, P. ¿Antiguo of flaso? El peritaje arqueológico con métodos luminiscentes. Ramírez Luna, A. et al., Evidencia por termoluminiscencia de ocupaciones posteriors a la caída del sitio arqueológico El Tajín, Mexico. Santibáñez, M et al., Dose-response characterization of gadolinium-infused polymer PAGAT dosimetry aimed at dose enhancement assessment. Alnaaimi, M. Estimation of patient Effective doses in positron emission tomography and computed tomography in Kuwait. Malthez, ALMC et al., Characterization and performance test of a new OSL/TL dosimeter for individual monitoring. Salas-Juárez, Ch. Thermoluminescence properties of new BaZrO3 phosphors exposed to beta particle irradiation. Machado Pereira, EL et al., Contribution of the MWCNT-ZrO2 addition on the dosimetric properties of PVDF. Singh, VP. et al., Study on photon interaction with normal and cancerous tissues. Oviedo Rivero, I et al., Base de datos INIS soporte informative para las investigaciones de dosimetría de estado sólido. vi 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 Singh, VP. et al., Photon absorption of calcium phosphate based teeth biomaterials in diagnostic radiology. Rafael Rosario, B. Síntesis y caracterización de nano cristales de fluoruro de litio dopados con plata (LiF:Ag). Malthez, ALMC. et al., Characterization and performance tests of a new OSL/TL dosimeter for individual monitoring. Mares, CE. et al., Sonido focalizado: Terapia oncológica para tejido transformado. Castañeda Palafox, SJ et al., Determinación de plata en sustratos biológicos. Vega-Carrillo, HR. et al., H*(10) debida a la radiación dispersada en un TomoLINAC. Almonte, A. et al., Dosimetric characterization of small photons beams of a novel linear accelerator using EDGE diode detector. Bradley, D. Novel media and mechanisms applied to radiation dosimetry. Baffa, O. Exotic dosimetric techniques. Hugtenburg, R.P. et al., Pulse-by-pulse dosimetry of IMRT with a diamond-based CVD detector. Berges, L. Experiencia cubana sobre el uso de la terapia electroquímica en cancer. vii 93 94 95 96 97 98 99 100 101 102 103 ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Respuesta termoluminiscente del dialuminato de calcio intrínseco e impurificado con Cr3+ Pablo Víctor Cerón Ramírez1,*, Miguel Ángel Vallejo Hernández1, Eduardo Montes Ramírez2, Luis Armando Díaz Torres3, José Antonio Irán Díaz Góngora2, Modesto Antonio Sosa Aquino1 1 2 Universidad de Guanajuato, 37150 León Gto., México Instituto Politécnico Nacional, 11500 Ciudad de México, México 3 Centro de Investigaciones en Óptica, 37150 León Gto., México * Email: [email protected] Resumen En numerosos trabajos se ha presentado la respuesta termoluminiscente (TL) del óxido de aluminio y se le han incorporado diversos dopantes para aumentar el número de defectos y modificar sus propiedades dosimétricas. En materiales afines como los aluminatos se han impurificado con iones trivalentes y se han determinado sus características ópticas. Debido a estos antecedentes surge la motivación de estudiar los aluminatos como posibles dosímetros termoluminiscentes. En este trabajo se presenta la síntesis de polvos de aluminato de calcio intrínsecos y dopados con Cr3+ por el método de combustión, para elaborar pastillas y evaluar su respuesta TL con distintas fuentes de radiación. El material obtenido fue caracterizado por DRX, fluorescencia de rayos X y UV-Vis; se encontró que pertenece a la fase monoclínica del dialuminato de calcio (CaAl4O7) con un tamaño de cristal de 55 nm, también se observó la presencia del Cr3+ en la red cristalina. Las muestras presentaron una buena respuesta TL para radiación UV, rayos X de una fuente de 70 kV y para gammas de Co-60. Los resultados encontrados muestran que el CaAl4O7 es un buen candidato para estudiar sus propiedades dosimétricas. Palabras clave: Termoluminiscencia; Aluminato de calcio; Dosimetría. 1 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. New investigations related with lanthanide-doped magnesium oxide obtained by glycine-based solution combustion synthesis: Exerting influence of addition of Li+ on thermoluminescence properties Victor Ramón Orante-Barrón1,*, Flor María Escobar-Ochoa1, María Alicia GortárezJiménez1, Gustavo Eduardo Sánchez-Ortega1, Catalina Cruz-Vázquez1, Rodolfo Bernal2 1 Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora Apartado Postal 130, Hermosillo, Sonora 83000 México 2 Departamento de Investigación en Física, Universidad de Sonora Apartado Postal 5-088, Hermosillo, Sonora 83190 México * Email: [email protected] Abstract The glycine molecule has a carboxylic acid group at one end and an amine group at the other end, both of which can participate in the complexation of metal ions. This “zwitterionic” character allows effective complexation with metal cations of different ionic size [1]. Novel MgO:Ln3+,Li+ (Ln: lanthanide) phosphors were obtained for the very first time by solution combustion synthesis (SCS) in which a redox combustion process between metallic nitrates and glycine at 500 °C was accomplished. Powder samples obtained were annealed at 900 °C during 2 h in air. Photoluminescence emission spectra showed characteristic lanthanides emission peaks. Thermoluminescence glow curves obtained after exposure to beta radiation of these samples, displayed maxima located at suitable temperatures for considering them as stable or dosimetric. Results from experiments such as dose response and fading showed that annealed MgO:Ln3+,Li+ powders obtained by SCS are promising materials for radiation dosimetry applications. [1] Chick L. A., Pederson L. R., Maupin G. D., Bates J. L., Thomas L. E., Exarhos G. J. (1990) Mater. Lett. 10: 6-12 Keywords: Magnesium oxide; Solution Combustion Synthesis; Lanthanide-doped; Thermoluminescence dosimetry. 2 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Novel thermoluminescence features of La2O3 phosphors obtained by an optimized urea-based solution combustion synthesis Victor Ramón Orante-Barrón1,*, Adriana Guadalupe Lara-González1, Juan Jesús Gutiérrez-Cañez2, Catalina Cruz-Vázquez1, Rodolfo Bernal3 1 Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora Apartado Postal 130, Hermosillo, Sonora 83000 México 2 Departamento de Ciencias Químico Biológicas de la Universidad de Sonora Apartado Postal 130, Hermosillo, Sonora 83000 México 3 Departamento de Investigación en Física, Universidad de Sonora Apartado Postal 5-088, Hermosillo, Sonora 83190 México * Buzón-e: [email protected] Abstract Novel thermoluminescence (TL) features of La2O3 are reported in this work. Novel La2O3 phosphor was obtained by an optimized solution combustion synthesis (SCS), in which a redox combustion process between lanthanum nitrate and urea at 500 °C is accomplished under stoichiometric conditions [1]. The powder samples obtained were annealed at 900 °C during 2 h in air. X-Ray Diffraction (XRD) results showed the hexagonal phase of La2O3 for annealed powder samples. The TL glow curve obtained after exposure to beta radiation of these samples, displayed two maxima located at ~ 101 °C, ~ 200 °C and a shoulder at ~ 247 °C. Results from experiments such as dose response and fading showed that annealed La2O3 powder obtained by SCS is a promising material for high-dose radiation dosimetry applications. [1] Shea, L. E., McKittrik, J. and Lopez, O. A. (1996). J. Am. Ceram. Soc. 79: 3257-3265. Keywords: Lanthanum oxide; Solution Combustion Synthesis; Thermoluminescence dosimetry. 3 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Synthesis and thermoluminescence characterization of lithium borate glasses doped with Dy3+ and Yb3+ and containing silver nanoparticles Janet Alejandra Elías Ángel, Miguel Ángel Vallejo Hernández, Pablo Víctor Cerón Ramírez, Modesto Antonio Sosa Aquino. División de Ciencias e Ingenierías. Campus León. Universidad de Guanajuato Loma del Bosque 103, Col. Lomas del Campestre 37150, León, Guanajuato, México. Buzón-e: [email protected] Abstract In this work, it was synthesized and characterized Lithium Borate Glasses doped with rare earths in different concentrations and containing Silver nanoparticles (SNP). The rare earths employed were Dy3+ and Yb3+. The Scanning Electron Microscope (SEM) shows the formation of SNP while absorption spectra of the samples show the presence of bands in 420 nm and 450 nm associated with the SNP (plasmon effect), as also bands at 750 nm, 800 nm, 875 nm, 1098 nm and 1278 nm respectively, belonging to the Dy3+ and one large peak at 976 nm belonging to the Yb3+. Emission spectra show two prominent bands at 480 nm and 574 nm, and one faint band at 665 nm, all bands under 364 nm pumping, and the fluorescence in the 550 nm and 590 nm spectral range enhanced two times. The TL response to UV irradiation was also studied, the glow curve shows significant dependence of the TL intensity with the increment of the SNP concentration in the samples. Keywords: Thermoluminescence; Glasses; Silver nanoparticles; Lithium borate; Rare earth. 4 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Efecto morfológico y termoluminiscente de LiF puro y dopado con Ce3+ usando surfactantes no-iónicos y catiónicos en el proceso de síntesis Esteban Rivera Pérez1, Modesto Antonio Sosa Aquino1, Miguel Ángel Vallejo Hernández1, Luis Armando Díaz Torres2, Ricardo Navarro Mendoza3, Héctor René Vega Carrillo4 1 División de Ciencias e Ingenierías, Universidad de Guanajuato 37150 León Gto., México. 2 Departamento de Espectroscopia de Materiales Avanzados y Nanoestructurados Centro de Investigación en Óptica, 37150 León, Gto., México. 3 División de Ciencias Naturales y Exactas, Universidad de Guanajuato 36050 Gto, Gto., Mexico. 4 Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas 98060 Zacatecas, Zac, México. Buzón-e: [email protected] Resumen Nuevas rutas de síntesis se enfocan en optimizar la composición de la fase, el tamaño de cristal y la morfología, con el objetivo de incrementar la respuesta termoluminiscente. En este trabajo se presenta un estudio sistemático sobre los efectos morfológicos y termoluminiscentes de cristales de LiF puro y dopado con Ce3+, sintetizados por el método de co-precipitación en presencia de los surfactantes: Pluronic F-127, PVP y CTAB. Los cristales obtenidos presentan estructura cristalina cúbica, los cuales fueron observados por Microscopia Electrónica de Barrido (MEB) y confirmados por Difracción de Rayos X (DRX). Los espectros de emisión y absorción muestras bandas características a la formación de centros de color F. En la caracterización Termoluminiscente (TL) se usaron fotones provenientes de un Tomógrafo de 6 MV y una fuente de Cs-137. Palabras claves: Surfactante; Termoluminiscencia; Cristales de LiF. 5 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Evaluation of collimator rotation for VMAT lung SBRT using flattening filter free Emmily Santos Sandrini1,2,*, Ademir Xavier da Silva2, Claudia Menezes da Silva1, Daniel Santana Lima Borges Figueiredo3 2 Nuclear 1 Grupo COI, Integrated Oncology Clinic, RJ, Brazil Engineering Program, Federal University of Rio de Janeiro, RJ, Brazil 3 Estacio de Sa University, RJ, Brazil *Email: [email protected] Abstract Volumetric modulated arc therapy (VMAT) allows fast delivery of stereotatic body radiotherapy (SBRT) for lung tumors [1-3]. In the present investigation discrepancies between the calculated dose distribution with different collimators rotations have been studied. Seventy six SBRT treatment plans were set up in the Eclipse Treatment Planning System using RapidArc planning technique with two diferente coplanar arcs arrangement (one full and two half arcs). For all the treatment plans, six diferente collimators rotations (0, 10, 20, 30, 45 and 90 degrees), 6MV x-ray flattened (6FF), 6MV and 10MV x-ray nonflattenes (6FFF and 10FFF) from a TrueBeam accelerator equipped with High-Definition 120MLC were used. All plans were calculated with Acuros XB (AXB) [4] and Anisotropic Analytical Algorithm (AAA). The comparisons were performed with a small and a large lesion with volumes of 3.16 cc and 39.2cc, respectively. The conformity index (CI), heterogeneity index (HI), conformity number (CN) and ratio of 50% prescription isodose volume to the PTV volume (R50) were determined for each plan. For all plans calculated with AXB the values found were higher than plan calculated with AAA, with the exception of the CN that presented lower value. Differences up to 20% were found. Discrepancies between collimator rotations were not significant for large lesion. However, plans with 90 and 0 degrees collimator rotations showed results worse than expected. Variation in CI of up to 38% was found in plans with full arcs, while in half arcs this difference was less than 10%. For R50 the higher diferences were found for 10FFF energy. Independently of calculation algorithm used, the collimator rotation impacts on dose distribution. For rotation between 10 to 45 degrees there were not found a significant variation meanwhile collimator rotation of 0 and 90 degree may impact on dose distribution resulting in unexpected dose variation. [1] Tyler, M.K. (2016), Journal of applied clinical medical physics, Vol. 17, No 1, pp 158-166 [2] Huang, B. (2015), Radiation Oncology, 10:53, DOI 10.1186/s13014-015-0357-0 [3] Li, X. (2013), Journal of applied clinical medical physics, Vol. 14, No 6, pp 195-204 [4] Kan, M. W. K. (2013), Hindawi Publishing Corporation BioMed Research International Volume, Article ID 692874, DOI 10.1155/2013/692874 Keywords: SBRT, lung, Flattened Filter Free. 6 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Thermoluminescence properties of new Dy doped ZnO phosphors exposed to beta particle irradiation R. Avilés-Monreal1*, C. Cruz-Vázquez2, R. Bernal1 1 Departamento de Investigación en Física, Universidad de Sonora. Apartado Postal 5-088, Hermosillo, Sonora 83190. México. 2 Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora. Apartado Postal 130, Hermosillo, Sonora 83000, México. * Buzón-e: [email protected] Abstract ZnO is a semiconducting material having a band-gap energy of 3.37 eV. It exhibits high radiation dose hardness, it is insoluble in water and has low toxicity [1]. It is known that their optical properties are modified by doping. In this respect, Dy is widely mentioned in the literature as an activator in luminescent phenomena [2,3]. Thermoluminescence (TL) is a reliable technique for the detection and measurement of ionizing radiation. Despite this, no reports on the TL properties of ZnO:Dy concerning their dosimetric capabilities are found in literature. In this work, the synthesis, structural and TL characterization of Dy doped ZnO is reported. Scanning electron microscopy (SEM) images of samples show 5 µm size agglomerates composed mostly by nanosized flakes-shaped particles. Energy Dispersive Spectroscopy confirmed the presence of Dy. The characteristic TL glow curves recorded using a 5 °C/s heating rate, show three maxima located at ~ 125 °C, ~ 200 °C and ~ 310 °C after beta particle irradiation exposure in the dose range from 0.5 to 512 Gy. The integrated TL increases by increasing the irradiation dose with no saturation clouds, with a linear behavior for doses at least up to 256 Gy. Also, The TL glow curve of ZnO:Dy phosphors was deconvoluted and the Kinetic parameters obtained by using the TLAnal computer program. Due to the dosage range and the position of the TL maximum, it is concluded that Dy doped ZnO is a promising phosphor material for application in radiation dosimetry. [1] Park H., Zhang S., Wei S., (2002), Physical Review B, 66, 073202-1- 073202-3. [2] McKeever S. W. S., (1985). Thermoluminescence of Solids, World Scientific, New Jersey. [3] Furetta C., Weng P., (1998). Operational Thermoluminescence Dosimetry, first ed. World Scientific, Singapore. Palabras clave: Thermoluminescence, ZnO, dosimetry, semiconductors. 7 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Effect of thermal annealing on the luminescence properties of Na doped ZnO R. Avilés-Monreal1*, C. Cruz-Vázquez2, R. Bernal1 1 Departamento de Investigación en Física, Universidad de Sonora. Apartado Postal 5-088, Hermosillo, Sonora 83190. México. 2 Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora. Apartado Postal 130, Hermosillo, Sonora 83000, México. *Email: [email protected] Abstract ZnO is multifunctional material with potential application, for example, in ultraviolet light emitting diodes, laser diodes, sensors, varistors, and solar cells. The band gap modification in semiconducting materials by doping or thermal annealing [1,2], remarkably influence their properties, including the thermoluminescence (TL) response. In particular, Na doping modifies the optical properties including the band gap energy and the luminescence features [1,3] . Despite this, no reports on the TL properties of ZnO:Na concerning their dosimetric capabilities are found in literature. In this work we report a study concerning the effect of different thermal annealing treatments on the TL features of Na doped ZnO phosphors. The characterized samples were synthesized by a chemical precipitation method and then sintered at 900 °C for 24, 48 or 72 h. The best reusability into successive irradiation-TL readout cycles were observed for the samples annealed at 900° C for 48 h. The characteristic glow curves of those samples show three maxima located at ~ 135 °C, ~ |235 °C and ~ 295 °C after exposure to beta particle irradiation in the dose range from 0.5 to 1,024 Gy. The integrated TL increases by increasing the irradiation dose with no saturation clouds, with linear response segmented in two regions over the whole dose range studied. The TL glow curve of ZnO:Na phosphors sintered at 900 °C for 48 h was deconvoluted using the TLAnal computer program. From the experimental results here reported, we conclude that the synthesized ZnO:Na phosphors are promising to develop new high performance TL dosimeters and suitable thermal annealing procedures can be used to improve the TL properties. [1] Park H., Zhang S., Wei S., (2002), Physical Review B, 66, 073202-1-073202-3. [2] Huang G., Wang C., Wang J., J. (2009), Phys. Condens. Matter, 21, 345802. [3] Yang X. P., Lu J. G., Zhang H., Huang J. Y., Ye C. L., Ye Z. Z., (2012), J. Appl. Phys.112, 113510. Keywords: Thermoluminescence; ZnO; Dosimetry; Semiconductors. 8 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Determination of kinetic parameters of thermally stimulated luminescence of magnesium oxide doped with lanthanum and lithium Flor María Escobar Ochoa1*, Victor Ramón Orante Barrón1, Catalina Cruz Vázquez1, Rodolfo Bernal2 1 Departamento de Investigación en Polímeros y Materiales de la Universidad de Sonora Apartado Postal 130, Hermosillo, Sonora 83000 México. 2 Departamento de Investigación en Física, Universidad de Sonora Apartado Postal 5-088, Hermosillo, Sonora 83190 México * Email: [email protected] Abstract In this work, thermoluminescence (TL) main features of novel magnesium oxide doped with lanthanum and lithium (MgO:La3+, Li+) are presented for the very first time. The phosphor was obtained by solution combustion synthesis (SCS) in which a redox combustion process between metallic nitrates and glycine at 500 °C was accomplished. Powder samples obtained were annealed at 900 °C during 2 hours in air. TL glow curves obtained after exposure to beta radiation of these samples, displayed three maxima located at ~ 88 °C, ~ 250 °C and ~ 332 °C. Dose response curve showed a linear trend within the interval of 1-16 Gy. TL glow curves were analyzed employing different methods for the determination of kinetic parameters, associated with the number and shape of the peaks from the glow curve. Such parameters are: activation energy (E), or depth of the traps, frequency factor (s), and kinetics order (b). In addition to TL, X- ray diffraction (XRD) and scanning electron microscopy (SEM) are included as structural characterization techniques. Keywords: Magnesium oxide; Lanthanum-doped; Solution combustion synthesis; Thermoluminiscence dosimetry. 9 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Whole-body 18F-FDG PET-CT scanning with CT for anatomical mapping: Radiation levels for oncologic diagnosis Priscila do Carmo Santana1*, Paulo Márcio Campos de Oliveira1,2, Arnaldo Prata Mourão3, Guilherme Neto de Pinho Carvalho1, Teógenes Augusto da Silva 2 1 Departamento de Anatomia e Imagem, Universidade Federal de Minas Gerais Belo Horizonte, Brasil 2 Centro de Desenvolvimento da Tecnologia Nuclear -CDTN/ CNEN Belo Horizonte, Brasil 3 Departamento de Engenharia Elétrica, Centro Federal de Educação Tecnológica Belo Horizonte, Brasil * Email: [email protected] Abstract The PET -CT is a method capable of detecting with great precocity minimum tumor areas (up to 4 mm) that can´t be seen in other tests, but later, when the tumor already has large and therefore more serious for the patient. PET- CT is a diagnostic technique that combines techniques nuclear medicine (PET), which gives rise to metabolic images, and radiology (CT), responsible for producing anatomic images, thus producing an image only with anatomical and functional information. To determine the effective dose from PET-CT exam was used two steps, one to determine the effective dose contribution caused by CT and another to evaluate the contribution from the radiopharmaceutical activity. For the evaluation of the effective dose from the CT imaging modality was used lithium fluoride thermoluminescent detectors activated with magnesium and titanium (LiF: Mg, Ti - TLD-100) Rod, inserted in anthropomorphic Alderson Randon® male phantom points corresponding the most radiosensitive organs and greater likelihood of exposure. After thermoluminescent detectors insertion, the phantoms were subjected to the same protocol of image acquisition which the patients were submitted, and the irradiation field of the CT skull base at the root of the thigh. As for the contribution determiner effective dose of the PET, we used estimates according to the biokinetic model proposed by ICRP 106 for the radiopharmaceutical 18F-FDG. In diagnostic PET scans, the activity radioactive injected into the patient is calculated based on their body mass. This work was considered a factor of 3.7 MBq / kg of patient. The average effective dose from the examination of PET-CT protocol for cancer study was (8,51 ± 0,17) mSv in male patients and (5,80 ± 1,57) mSv in female patients. Exams in male patients were possible to observe the high level of radiation in the thyroid, since this organ dose is derived mostly by CT irradiation, since this body is within the field of radiation during CT image acquisition. Exams in female patients was possible to observe the high level of radiation in the bladder, marrow and stomach, since this organ dose is derived mostly by CT irradiation, since this body is within the field of radiation during CT image acquisition. The effective dose from CT corresponds to approximately 43% of the effective dose in a PET-CT. Study about dose reduction in PET-CT exams is necessary to the reduction radiation levels during CT image acquisition and activity factor for mass patients decreased for 18F-FDG incorporation and image acquisition of PET. [1] Huang, B., et al. (2009). Radiology, 251 :166-174. [2] ICRP Publication 106 ( 2008). [3] ICRP Publication 103 ( 2007). Keywords: PET-CT, 18F-FDG, Dose estimation, Whole-body scanning. 10 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Respuesta termoluminiscente del Y2O3:Ce,Eu irradiado con rayos X Francisco del Rosario Sánchez Jáquez1 y Modesto Antonio Sosa Aquino2 1 Escuela de Ingeniería Universidad APEC Apartado Postal No.2867, Código Postal 10107, Santo Domingo, República Dominicana. 2 División de Ciencias e Ingenierías, Campus León Universidad de Guanajuato, México Buzones-e: [email protected], [email protected] Resumen Se ha estudiado la respuesta termoluminiscente de diversos materiales al ser irradiados con rayos X, y se han determinado los parámetros que caracterizan el orden de la cinética del material, profundidad de trampas y frecuencia. El objetivo de este trabajo fue caracterizar la respuesta termoluminiscente de dosímetros a base de óxido de itrio (Y2O3) irradiados con rayos X. Para ello se midió y analizó la respuesta termoluminiscente del dosímetro Y2O3:Ce,Eu al exponerlo a un campo de radiación de rayos X, se usaron cinco niveles de radiación: en el primero se usó un potencial de 53.5 kV y una carga de trabajo de 5.6 mAs, en el segundo: 70.0 kV, 12.5 mAs; en tercero: 81.0 kV, 20.0 mAs; en el cuarto: 109 kV, 32 mAs; en el quinto, 121 kV, 80.0 mAs, aplicando un rango de exposición entre 17.7 y 40 R. La irradiación se hizo exponiendo la muestra a 104 cm del foco del tubo de rayos X. Para obtener las lecturas de la respuesta termoluminiscente, se usó un equipo lector marca Harshaw TLD 3500. Los datos captados por el lector fueron procesados mediante el software WinREMS. El protocolo de borrado fue el siguiente: se colocaron los dosímetros ya leídos, una hora en la mufla Terlab MA12D a una temperatura de 400 ± 1 ºC, se retiraron los dosímetros y se dejaron a temperatura ambiente 20 ºC durante 20 min. Luego fueron colocados en el horno de alta temperatura Binder ED23 a 100 ± 1 ºC durante 2 horas. A las curvas de brillo se les realizó la deconvolución, mediante el software WebPlotDigitizer v3.8, y se obtuvieron los picos individuales de las cuevas de brillo. Encontramos que: Los materiales sintetizados presentan una buena respuesta termoluminiscente al ser irradiados con rayos X. Sin embargo, sólo uno de los dosímetros, de óxido de Itrio dopado con Cerio al 0.5%, mostró una respuesta relativamente lineal en el rango de dosis aplicado. El análisis realizado a la curva de brillo del óxido de Itrio dopado con Cerio al 0.5%, aplicando el método de los tres puntos para la determinación de los parámetros, mostró que este material presenta un orden de cinética b = 1. Palabras clave: Irradiación; Curva de brillo; Deconvolución. 11 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Síntesis y caracterización termoluminiscente de vidrios de fosfato activados con iones de Dy3+ que contienen nanopartículas de Plata Miguel Ángel Vallejoa*, Luis A. Díaz-Torresb, Mario Pereza, Pablo Víctor Cerona, Ricardo Navarroc, Carlos Villaseñora, Modesto Antonio Sosaa. a Universidad de Guanajuato, Campus León, División de Ciencias e Ingenierías Loma del Bosque 103, Colonia Lomas del Campestre 37150 León, Gto. México b Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (GEMANA) Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto., México c Universidad de Guanajuato, Campus Guanajuato, División de Ciencias Naturales y Exactas Cerro de la Venada S/N, Pueblito de Rocha C.P. 36040 Guanajuato, Gto. México *Buzón-e: [email protected] Resumen Se sintetizaron vidrios de fosfato activados con iones de Dy3+ y que contienen nanopartículas de Plata (SNP por sus siglas en ingles). En este trabajo se reporta la caracterización fotoluminiscente de vidrios de fosfato de sodio activados con iones de Dy3+ y que contienen SNP por medio de sus espectros de Absorción y Emisión. Se estudio el efecto que provocan las SNP en la respuesta termoluminiscente de las muestras. Se muestra la formación de la nucleación de las SNP por medio de la técnica de microscopia SEM (Scanning Electron Microscopy). El espectro de Absorción muestra la influencia de las SNP en las bandas de absorción centradas en 350 nm y 425 nm ambas asociadas al Dy3+, en el mismo espectro se puede ver las bandas de absorción centradas en 750 nm, 800nm, 875 nm, 1098 nm, 1278 nm y 1675 nm pertenecientes al Dy3+. Los espectros de emisión muestran dos bandas prominentes centradas en 480 nm y 574 nm y una pequeña centrada en 665 nm correspondientes a las transiciones 4F9/26H15/2, 4F9/26H13/2 y 4F9/26H11/2, las muestras fueron bombeadas con una longitud de onda de 364 nm. La intensidad de las emisiones centradas en 550 nm y 590 nm aumenta 4 veces. La respuesta termoluminiscente muestra una dependencia significativa, aumentando su intensidad conforme se incrementan las SNP en las muestras. Keywords: Vidrios de fosfato; Respuesta Termoluminiscente; Nanoparticulas de Plata; Tierras raras. 12 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Determinación del K-40 en Croquetas Martha I Escalona Llaguno1/*, Guillermo E Campillo Rivera1/&, Héctor René Vega-Carrillo1, Eduardo García Sánchez2 1 Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas C. Ciprés 10, Fracc. La Peñuela, 98060 Zacatecas, Zac. México 2 Unidad Académica de Ingeniería Eléctrica de la Universidad Autónoma de Zacatecas Av. Ramón López Velarde 801, 98060 Zacatecas, Zac. México Buzon-e: *[email protected], &[email protected] Resumen La salud de las mascotas depende de varios factores, uno de los más importantes es la calidad de su alimentación. El perro (Canis lupus familiaris), es un mamífero carnívoro de la familia de los cánidos que forma parte de las mascotas más aceptadas. Para su alimentación es común que se usen alimentos industriales como las croquetas que ofrecen muchas ventajas, sin embargo también contribuyen con la ingesta de radioisótopos que puede afectar su salud. El potasio es un elemento esencial para la salud, en forma natural existen 3 isótopos (K-39, K-40 y el K41) EL K-40 es radiactivo con 1.248x109 años de vida media que al decaer emite partículas beta y fotones de 1.42 MeV. En este trabajo se determinó la actividad de potasio 40 en 3 marcas de croquetas: Dog Chow cachorro, Dog Chow adulto, Poder canino y Exceed; como estándar se usó KCl y como control se usó chícharo deshidratado. Las croquetas y el chícharo se molieron y se pesaron 160 gramos de cada muestra, del KCl y del chícharo que se colocaron en contenedores Marinelli que se midieron con sistema espectrométrico para rayos  con un centellador de NaI(Tl) de 7.62 cm de diámetro y 7.62 cm de altura. Se encontró que la actividad de K-40 en todas las marcas medidas es de 5.0 ± 0.3 Bq por gramo de croquetas. Palabras clave: K-40; Croquetas; NaI(Tl); Marinelli; Rayos . 13 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Nano magnetita recubierta de oro: Terapia oncológica alternativa con hipertermia magnética Teodoro Córdova Fraga1,*, Octavio Jiménez González1, Gustavo Basurto Islas1, Juan Carlos Martínez Espinosa2 1 DCI, Universidad de Guanajuato campus León, GTO, Mex. UPIIG, Instituto Politécnico Nacional, Silao de la Victoria, GTO, Mex. 2 Buzón-e: [email protected] Resumen La hipertermia magnética localizada realizada mediante el uso de nanopartículas es uno de los procedimientos más prometedores para el tratamiento del cáncer. Este trabajo presenta la síntesis de nanopartículas de magnetita (Fe3O2) mediante el método de descomposición térmica. Posteriormente estas nanopartículas fueron recubiertas de oro y suspendidas en fase acuosa. Como resultado se obtuvieron nanopartículas susceptibles de ser calentadas mediante la aplicación de un campo magnético alterno o bien a través del uso de radiación infrarroja. Como una característica adicional se tiene que estas nanopartículas son biocompatibles gracias a su recubrimiento áureo. Las nanopartículas sintetizadas pueden ser funcionalizadas mediante la conjugación de una molécula (Aptámero anticuerpo, péptido, etc.) cuyo blanco sea una célula cancerosa con el fin de adherirle a esta el complejo nanopartícula-marcador, para posteriormente realizar un calentamiento con el objetivo de inducir muerte celular. En conclusión, las nanopartículas sintetizadas permiten brindar un tratamiento alternativo para cáncer mediante el uso de hipertermia localizada, ya sea utilizando calentamiento magnético o infrarrojo. Palabras clave: Hipertermia; Nanopartículas; Tratamiento de cáncer. 14 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Producción de Neutrones en la Interacción de Electrones con una Laminilla Dispersora Tzinnia Gabriela Soto-Bernal1/*/&, Antonio Baltazar-Raigosa2 Diego Medina-Castro1/&, Hector Rene Vega-Carrillo3 1 Programa de Doctorado en Ciencias Básicas (Ciencias Nucleares) Unidad Académica de Estudios Nucleares Universidad Autónoma de Zacatecas 2 Programa de Doctorado en Ingeniería y Tecnología Aplicada Unidad Académica de Ingeniería Eléctrica, Universidad Autónoma de Zacatecas. 3 Unidad Académica de Estudios Nucleares Universidad Autónoma de Zacatecas. Zacatecas, Zac. México * Buzón-e: [email protected] & Becari@ CONACyT Resumen Cuando un LINAC para radioterapia opera con voltajes de aceleración superiores a los 8 MV se producen neutrones como radiación secundaria. Estos depositan una dosis indeseable y no despreciable en el paciente. Dependiendo del tipo de tumor, su localización en el cuerpo y las características del paciente, el tratamiento del cáncer con un LINAC se hace con haces de fotones o de electrones, que producen neutrones a través de reacciones (γ, n) y (e, e´n) respectivamente. Debido a que la sección eficaz de la reacción (, n) es 137 veces mayor que la reacción (e, e´n), la mayoría de los estudios se han enfocado a los photoneutrones. Cuando un LINAC opera con haces de electrones, el haz que sale del deflector magnético se hace incidir en la laminilla de dispersión con el fin de provocar interacciones cuasi-elásticas y expandir la distribución espacial de los electrones; en su interacción con la laminilla los electrones producen fotones y éstos a su vez producen neutrones. Debido a la eficiencia radiobiológica de los neutrones y a las formas con que interactúan con la materia, es importante determinar la producción de neutrones en LINACs operando en modo electrón. El objetivo de este trabajo es determinar las características de los fotones y los neutrones que se producen cuando un haz de electrones mono-energéticos de 2 mm de diámetro (pencil beam) se hace incidir sobre una laminilla de tungsteno de 1 cm de diámetro y 0.5 mm de espesor localizada en el centro de un cascarón esférico de tungsteno de 10 cm de espesor, usado para representar el cabezal del acelerador. El estudio se hizo mediante métodos Monte Carlo con el código MCNP6 para haces de electrones de 12 y 18 MeV. Se estimaron los espectros de fotones y neutrones en 6 detectores puntuales, cuatro se colocaron en diferentes puntos equidistantes del centro de la laminilla, y los otros dos se ubicaron a 50 cm y a 1 m del haz de electrones, simulando el cabezal totalmente cerrado. Palabras clave: Electrones; Neutrones; Laminilla dispersora; LINAC; Monte Carlo. 15 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Análisis de los niveles de radioisótopos en muestras ambientales de Dos Bocas, Tabasco Cruz Daniel Mandujano-García1,2,*, Ma. Teresa Herrera-Dorantes2, Ana Ruth Nava-Huerta2, Julieta Maldonado-Sánchez2, Guillermo Manjón1, Ignacio Vioque1, Modesto Sosa3 and Pedro Luis Ardisson2 1 Departmento de Física Nuclear Aplicada II, Universidad de Sevilla 41012- Sevilla, España 2 Departmento de Recursos del Mar, Cinvestav. 97310 Mérida, Yucatán, México 3 Departamento de Ingeniería Física, Universidad de Guanajuato 37150 Guanajuato, México *Buzón-e: [email protected] Resumen Las actividades humanas pueden generar y emitir al ambiente materiales con contenido radioactivo de origen natural (NORM: naturally occurring radioactive materials). Las descargas de agua congénita por parte de las actividades petroleras introducen en los ecosistemas marinos elevados niveles de isótopos de radio, resultando en un potencial problema radioecológico. En este trabajo se presenta una evaluación de los niveles de isótopos de radio en agua, sedimento y organismos marinos de la zona costera de Dos Bocas, Tabasco, afectada por las actividades petroleras en el sur del Golfo de México. La caracterización radiométrica de las muestras es realizada por espectrometría gamma de alta resolución con detectores de germanio hiperpuro (HPGe). Los resultados obtenidos en las muestras analizadas indican que los niveles de radio en agua son menores a los límites de detección, mientras que en sedimento los isótopos Ra-226, Ra-228 y Ra-224 presentan valores con rangos de 8-81, 10-134 y 11-130 Bq/kg, respectivamente. Una discusión de estos resultados y los correspondientes a organismos marinos es llevada a cabo para analizar la huella de las descargas de NORM en esta región. Palabras clave: Radioactividad ambiental; NORM; Radioecología. 16 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Optimization by Monte Carlo method of photon fluence from the X-ray beam spectrum in a bimodal tomographic system H. Olaya Dávila1, S.A. Martinez-Ovalle1/*, H. Castro2, H.R. Vega-Carrillo3 1 Universidad Pedagógica y Tecnológica de Colombia Tunja-Boyacá, Colombia 2 Universidad Nacional de Colombia Bogotá D.C.-Colombia 3 Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas Zacatecas, Zac. Mexico * Email: [email protected] Abstract A bimodal tomographic system, having a RTW MCBM 65B-50Mo X-ray tube and a XPAD3s semiconductor camera, that contains 8 bars, each one with 67200 hybrid pixels was modeled with the GEANT4 code. Several conical X-ray spectra were estimated, particularly the spectrum with a maximum energy of 17.4 keV used in tomography on small animals. [1]. Three phantoms, located in the tomographic center, were included in the model to evaluate the image quality and its magnification. In the calculations various photon fluences were used assuming an average angular velocity of 360o per minute. Modeled cases were actually measured, here the images were recorded and analyzed in 2D through ROOT software toolkit in virtual XPAD3 detector. The quantitative method 20%80% of the maximum intensity of radiation was used for obtain the contouring of the phantoms, this method is used in radiotherapy and radiodiagnosis imaging. For this purpose, the images were taken to DICOM format in order to estimate the optical density of the contours and to evaluate the image quality in function of the photon fluence aiming to have a good image quality, the optimum photon fluence reducing the absorbed doses in the individuals. The aim of this work was to determine the optimal fluence, in order to validate it with realistic fluences used in the tomographic prototype ClearPET /XPAD-CT, and to make an intercomparison with the absorbed doses measured with detectors located in the tomographic center. [1] Hertel, H.R. MATERIALS FOR DOSIMETRY, McGraw Hill, (2000). [2] Hammonet, M. (2016). Tomographie hybride simultanee TEP/TDM combinant detecteurs á pixels hybrides et modules phoswich. Marseille: Aix Marseille Université. [3] Kluetz, P., & et al. (2000). Clin Pos Imag, 3: 223-230. [4] Mosset, J., & et al. (2006). IEEE Trans.Nucl.Sci, 53: 25-29. [5] Nicol, S. (2010). Étude et construction d'un tomographe TEP/TDM pour petits animaux. Marseille: Université Aix Marseille. Keywords: Monte Carlo simulation, X rays, diagnostic image, tomography 17 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Integration of Fricke gel dosimetry with Ag nanoparticles for experimental dose enhancement determination in theranostics J. Vedelago1,2, F. Mattea3,2, M. Valente1,2,4,* 1 2 Instituto de Física E. Gaviola - CONICET, Av. M. Allende s/n, Córdoba, Argentina. Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Universidad Nacional de Córdoba, Av. M. Allende s/n, Argentina. 3 Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, CONICET, Córdoba, Argentina. 4 Centro de Física e Ingeniería en Medicina - CFIM & Departamento de Ciencias Físicas, Universidad de La Frontera, Francisco Salazar 1145, Temuco, Chile. * Email: [email protected] Abstract The use and implementation of nanoparticles in medicine has grown exponentially in the last twenty years. Their main applications include drug delivery, theranostics, tissue engineering and magneto function. Dosimetric techniques can take advantage of inorganic nanoparticles properties and their combination with gel dosimetry techniques could be used as a first step for their later inclusion in radio-diagnostics or radiotherapy treatments [1]. This work presents preliminary results of properly synthesized and purify silver nanoparticles integration with Fricke gel dosimeters. Used nanoparticles presented mean sizes ranging from 2 to 20 nm, with a lognormal distribution. Xylenol orange concentration in Fricke gel dosimeter was adjust in order to allow sample’s optical readout, accounting nanoparticles plasmon. Dose enhancement was assessed irradiating dosimeters setting Xray beams energies below and above silver K-edge. [1] Mattea, F. et al. (2017). Rad. Phys. Chem. 130: 442-450. Keywords: Fricke gel dosimetry; Ag nanoparticles; Dose enhancement. 18 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Análisis del diseño de un tubo de rayos X utilizando MCNP José Domingo Peña Vidal1,*, Modesto Sosa Aquino1, Pablo Víctor Cerón1, Miguel Ángel Vallejo1, Héctor René Vega Carrillo2 1 División de Ciencias e Ingenierías, Universidad de Guanajuato Loma del Bosque #103, Lomas del Campestre, C.P. 37150. León, Gto., México. 2 Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas Ciprés #10, Fraccionamiento La Peñuela, Zacatecas, México. *Buzón-e: [email protected] Resumen En este trabajo se presenta el análisis Monte Carlo de los rayos X producidos por un tubo de rayos X rotatorio de la marca SIEMENS que se usa en tomógrafos de uso clínico. El trabajo se hizo con el código MCNP6 con el que se modeló el tubo y se calcularon los espectros primarios de rayos X producidos durante la interacción de electrones monoenergéticos de 130 keV. Los espectros de rayos X se obtuvieron variando algunos parámetros como: el ángulo del ánodo (15 a 20 grados), el tipo de blanco (Tungsteno, Molibdeno y Rodio) y el espesor del filtro (3, 5, 10 y 15 mm). Con el fin de tener una buena estadística se usaron 107 historias. Mediante los estimadores, f2 y f5, se estimaron los espectros de rayos X y las fluencias totales. Esta información será usada para calcular la dosis absorbida en el cristalino y la glándula tiroides en pacientes sometidos a procedimientos de radiodiagnóstico. Palabras clave: MCNP6; Tubo de rayos X; Tally. 19 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Type testing of a locally made LiF:Mg,Ti +PTFE TLD for its use as a personal dosimeter Juan Azorín1/*, Eugenio Torijano1, Claudia Azorín2 1 Universidad Autónoma Metropolitana, Unidad Iztapalapa Mexico City, Mexico 2 Unidad Profesional Interdisciplinaria de Ingeniería y Ciencias Sociales y Administrativas Instituto Politécnico Nacional, Mexico City, Mexico *Email: [email protected] Abstract Our research group has developed a thermoluminescence (TL) phosphor based on LiF:Mg,Ti. This material can be used as a personal dosimeter including whole-body, environmental, medical, and extremity monitoring by making pellets of LiF:Mg,Ti +PTFE. The manufacturing process includes purifying, growing doped LiF, grinding, sieving, mixing with PTFE, and pressing at room temperature, to obtain pellets of 5 mm diameter and 0.8 mm thickness This final process transforms the material directly from a powder to its final form of LiFμMg,Ti +PTFE pellets. This process provides the benefits of better batch uniformity and excellent dimensional consistency. The testing is described that was performed for the purpose of accepting the LiF:Mg,Ti+PTFE material as a personal TL dosimeter. Tests performed include reproducibility, batch homogeneity, linearity, detection threshold, and light sensitivity. Results of extensive type testing carried out with reference to the international standard IEC 62387[1] are presented. This test applies to TLD systems that are used for measuring the personal dose equivalents Hp(10) or Hp(0.07) or the ambient dose equivalent H*(10) for external photon or beta radiation in the dose range from 0.01 mSv to 10 Sv. [1] IEC 62387 ed1.0, Radiation protection instrumentation - Passive integrating dosimetry systems for personal and environmental monitoring of photon and beta radiation (2012), International Electrotechnical Commission. ISBN 978-2-83220-518-1 Keywords: Homemade TLD; Dosimetry; Testing. 20 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Matriz respuesta de volúmenes regulares de moderador con detector de 3He mediante métodos Monte Carlo Antonio Baltazar-Raigosa1/*, Tzinnia Gabriela Soto-Bernal2/*/&, Diego Medina-Castro2/&, Hector Rene Vega-Carrillo1/3, José Manuel Ortiz Rodríguez1, Luis Octavio Solis Sánchez1, Rodrigo Castañeda Miranda1 1 Programa de Doctorado en Ingeniería y Tecnología Aplicada Unidad Académica de Ingeniería Eléctrica de la Universidad Autónoma de Zacatecas Zacatecas, Zac. México 2 Programa de Doctorado en Ciencias Básicas (Ciencias Nucleares) 3 Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas Zacatecas, Zac, México * Buzón-e: [email protected], & Becari@ CONACyT Resumen En las últimas tres décadas el uso de los métodos Monte Carlo, para la estimación de los fenómenos físicos asociados con la interacción de la radiación con la materia, se ha incrementado considerablemente. La razón se debe al aumento en las capacidades de cómputo y a la reducción de los precios de las computadoras. Los métodos Monte Carlo permiten modelar y simular sistemas reales antes de su construcción, ahorrando tiempo, costos. Los mecanismos de interacción entre los neutrones y la materia son diversos y van desde dispersión elástica hasta la fisión nuclear; para facilitar la detección de los neutrones se requiere moderarlos hasta alcanzar el equilibrio electrónico con el medio a condiciones estándar de presión y temperatura, en este estado la sección eficaz total del 3He es grande. El objetivo del presente trabajo fue estimar la matriz respuesta de un detector proporcional de 3He usando volúmenes regulares de moderador mediante métodos Monte Carlo. Se usaron fuentes monoenergéticas de neutrones con energías de 10-9 a 20 MeV y moderadores de polietileno de diferentes tamaños. Los cálculos se hicieron con el código MCNP5, el número de historias para cada combinación detector-moderador fue lo suficientemente grande para obtener errores menores al 3%. Encontramos que para moderadores pequeños la mayor respuesta se obtiene para neutrones de menor energía, al aumentar la dimensión del moderador observamos que la respuesta disminuye para neutrones de menor energía y aumenta para neutrones de mayor energía. La suma total de las respuestas de cada moderador permite obtener una respuesta cercana a una función constante. Palabras clave: Neutrones; Moderador; Detector Activo; Monte Carlo. 21 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. An overview on preparation and characterization of calcium sulfate for thermoluminescence dosimetry (TLD) Juan Azorín Universidad Autónoma Metropolitana, Unidad Iztapalapa Mexico City, Mexico Email; [email protected] Abstract Thermoluminescence dosimetry (TLD) is used in many scientific and applied fields such as radiation protection, radiotherapy, industry, and environmental and space research, using many different materials known as phosphors. The basic demands of a TLD material are: good repeatability, low hygroscopicity, and high sensitivity for very low dose measurements and good response at high doses in radiotherapy and in mixed radiation fields. Calcium Sulfate (CaSO4) is one of the most sensitive TL phosphors used in dosimetry. CaSO4 doped with rare earths are the most interesting phosphors in CaSO4 series, due that their response is considerably stable. The CaSO4:Dy and CaSO4:Tm phosphors have been used as ionizing radiation dosimeters particularly for low-dose measurements. CaSO4 has aroused interest of scientists since the decade of 1970s due its good TL properties. Since then, considerable work has been done on CaSO4 singly-doped and co-doped phosphors, resulting Dy and/or Tm doped CaSO4 TL phosphors highly attractive for TLD due to their desired TL characteristics. This paper presents an overview, including synthesis methods employed for the production of this material, and the TL properties that have had significant effect on the TLD potential of such compound along with the detailed information on TL measurement procedure specifications. Keywords: dosimeter. Preparation; Characterization; 22 ISSSD 2017 Book of abstracts Calcium sulfate; Thermoluminiscente ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Thermoluminescent properties of polycrystalline carbon doped LaAlO3/La(OH)3 by solid state reaction for application in UV dosimetry Neriene Alves1,*, Wilmar Barbosa Ferraz2, Luiz Oliveira de Faria1,2 1 Department of Nuclear Engineering, Federal University of the State of Minas Gerais Av. Antônio Carlos, 6627, CEP. 31270-901 Belo Horizonte, MG, Brasil. 2 Nuclear Technology Development Center Av. Antonio Carlos 6627, C.P. 941, 30161-970 Belo Horizonte, MG, Brasil * Email: [email protected] Abstract Different materials have been employed for monitoring UV radiation using thermoluminescence, such as ZrO2:Cu and a-Al2O3:C[1-3]. It is well known that UV radiation can induce certain deleterious effects, such as erythema, painful inflammation of the membrane of the eye and skin cancer[4, 5]. Therefore, it has been pushing the research for producing new and high performance UV sensitive TL materials. There is an increasing interest in the development of new TL materials for ultraviolet (UV) dosimetry purposes, owing to simplicity of the sample readout compared to other techniques. In this perspective this paper reports the thermoluminescence (TL) properties such as glow curves analysis, dose response linearity and some dosimetric characteristics were evaluated. Pure and carbon doped lanthanum aluminate/lanthanum hydroxide were performed by solid state reaction method by using four different combinations of Al2O3 , La2O3 and carbon atoms during the synthesis process. Lanthanum aluminate polycrystals were synthesized by mixing stoichiometrics amounts of aluminum and lanthanum oxide and 0.1wt.% of carbon, and annealing at 1700°C for two hours in hydrogen atmosphere. The crystalline samples were investigated after exposure to different UV radiation doses. The effect of different syntheses on the TL glow curves structures is also investigated and discussed. The X-ray diffraction analysis revealed the nucleation of rhombohedral LaAlO3 crystallographic phase, however a huge percentage (63%) of La(OH)3 has been also identified in all compositions. UV-Vis and FTIR spectrometry and SEM micrographs were used for samples characterization. The UV irradiations were carried out using a commercial 8W UV lamp. TL output measurements were obtained in a RISO TL/OSL reader. TL glow curves show that all compositions investigated have high TL sensitivity to UVR. TL glow curve deconvolution methods were performed to analyze the sets of TL glow curves. A good linear dose response over the dose range from 0.21 to 1.26 mJ/cm2 has been observed in two samples. [1] [2] [3] [4] [5] CHANG, C. L., H. (2006). Health Phys., 92: 242 - 250. MORALES-HERNÁNDEZ, A.(2016). Appl. Rad. Isot., 118: 12-17. RIVERA, T. (2007). Radiat. Meas. 42: 665-667. AKSELROD, M. S. (1990). Radiat. Prot. Dosim. 32: 15-20. MEINANDER, O. K. S. B., M. (2006). Appl. Opt., 45: 5346 – 5357. Keywords: Thermoluminescence; LaAlO3; La(OH)3; UV Dosimetry. 23 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Propiedades dosimétricas de α-Al2O3:Tm+PTFE Pedro R. González 1/*, Demetrio Mendoza-Anaya1 , Hugo J. Virafuentes-Chávez2 1 Instituto Nacional de Investigaciones Nucleares C.P. 52750, Ocoyoacac, Estado de México 2 Tecnológico de Estúdios Superiores de Jocotitlán C.P. 50700, Jocotitlán, Estado de México *Buzones-e: [email protected]; [email protected] Resumen En este trabajo, se presentan los resultados de la caracterización dosimétrica del α-Al2O3, dopado con iones de Tm3+, obtenido por el método de combustión de soluciones. Con el polvo policristalino obtenido, se elaboraron dosímetros en forma de pastillas, usando como aglutinante politetrafluoetileno, α-Al2O3+PTFE. Antes de exponerse a la radiación los dosímetros se les dio un tratamiento térmico de borrado a 350 °C durante 30 minutos. La curva de brillo presentó el pico dosimétrico en 190 °C, su respuesta termoluminiscente es lineal en el intervalo de dosis de 1 a 50 Gy de radiación gamma de 60Co, presentó ±1.8 %DS en la prueba de reproducibilidad, durante diez ciclos de borrado térmico, irradiación y lectura. Sin embargo, para propósitos de dosimetría se debe tomar en consideración su fading, que durante los primeros diez días es del orden del 10 %, sin embargo, durante dos meses es cercano al 40%. Usando la curva de brillo del material, se determinaron los parámetros cinéticos por el método de deconvolución, donde la energía del pico dosimétrico presentó una cinética de orden general, b=1.83, una energía o profundidad de las trampas, E=1.68 eV y un factor de frecuencia, s=1.94x1017 s-1. Por los resultados mostrados, este material resulta promisorio para dosimetría de la radiación en el campo de la Física Médica. Palabras clave: Detectores de estado sólido; Termoluminiscencia, Dosimetría. 24 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Relevance of the electron source size in simulations of linear accelerators using the Monte Carlo method Reginaldo Gonçalves Leão Junior1,2, Arnaldo Prata Mourão Filho1,3, Rômulo Verdolin Sousa2, Arno Heeren de Oliveira2 1 Department of Electrical Engineering, Instituto Federal de Minas Gerais Formiga, MG, Brazil 2 Department of NuclearEngineering, Universidade Federal de Minas Gerais Belo Horizonte, MG, Brazil 3 Centro Federal de Educação Tecnológica, Belo Horizonte, MG, Brazil * Email: [email protected] Abstract In this study, has been investigated changes caused by a small x-ray field due to the variation in the parameters that determines the radius of the electron source in a computer model of a linear accelerator for use in Monte Carlo techniques. Fields of interest for work, were small fields used in most modern techniques as Stereotatic Radioation Therapy (SRS) and Intensity Modulated Radiation Therapy(IMRT) and the collimation method used for obtaining these fields were SRS cones with nominal diameter of 9 mm, 21 mm and 33 mm in the isocenter. Computational resources used were BEAMnrc code for modeling the aclerador, and DOSXYZnrc code for modeling the water phantom and dosimetry. The simulations showed a high variation of the energy fluency in the target base when the size of the electron source is modified, also showed that the sizes of the radiation fields change significantly when radius larger than 0.1 cm are used and that the dosimetric variability in off axis ratios may reach 30% in strategic positions as the nominal field limits of the cone. Thus, the data show that the improper choice of electron source of the beam can significantly impair the overall performance of the accelerator and that such errors tend to propagate to the computed dose values. [1] P. Mayles, A. Nahum, J.C. Rosenwald, Handbook of Radiotherapy Physics: Theory and Practice, Taylor & Francis Group, Boca Raton , (2007) [2] William R. Hendee, Series Editor. Monte Carlo Techniques in Radiation Therapy , Taylor & Francis Group, Boca Raton & USA (2013) [3] R. G. Leão. Jr., A. H. de Oliveira, R. V. Sousa, A. P. Mourão, "Modeling and commissioning of a Clinac 600 CD by Monte Carlo method using the BEAMnrc and DOSXYZnrc codes", International Nuclear Atlantic Conference INAC 2015 , São Paulo & Brazil (2015). Keywords: Monte Carlo; Small Fields ; Source Size. 25 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Assessment of effective radiation dose to patients in certain radiographic examinations in Alkharj city Abdelmoneim Sulieman1,*, Omar Serhan2, Mustafa Mahmoud1, Mohammed Alkhorayef3,4, David Bradley4,5 1 Prince Sattam Bin Abdulaziz University, College of AppliedMedical Sciences, Radiology and Medical Imaging Department, Alkharj, Saudi Arabia 2 Radiology Department, King Khalid Hospital, Alkharj, Saudi Arabia 3 Department of Radiological Sciences, College of Applied Medical Sciences, King Saud University, PO Box 10219 Riyadh 11433, Saudi Arabia 4 Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, UK 5 Sunway University, Institute for Healthcare Development, Jalan Universiti, 46150, PJ, Malaysia * Email: [email protected] Abstract Radiation exposures from medical applications typically account for in excess of 90% of radiation dose from artificial sources, in particular increasing with greater use of computed tomography (CT). The latter contributes > 70% of the collective dose. Over the last three decades the per–capita effective dose has increased by some six-fold, from 0.5 mSv to 3.0mSv. With radiation risk increasing as a result of increased exposure, repeats included, and most signficantly among the young, evaluation of medical exposure dose is required to ensure that the radiation dose is low as reasonably achievable. The current study seeks to evaluate the radiation dose to patients during certain CT and conventional radiological procedures, also estimating the associated risks. Calibrated X ray machines equipped with a Kerma Area Product (KAP) meter were investigated in this study, analysed with software developed at the National Radiological Protection Board (NRPB; now Public Health England), estimating organ and effective doses for a total of 159 patients at the Department of Radiology, King Khalid Hospital, Alkharj, Saudi Arabia. In regard to CT doses, a 16 slice Siemens Sensation Multislice CT Scanner (MSCT) was studied, with exposure-related parameters taken into account, including: gantry tilt, peak kilovoltage (kVp), tube current (in units of mA), exposure time, slice thickness and number of slices. The mean patient effective doses (in units of mSv) for CT chest, abdomen, spine and brain were respectively: 7.1±2.3 (3.2-10.5), 6.7±1.52 (4.5-9.5), 13.2±2.0 (4.7-26.7), 1.7±0.8 (0.31-2.6). An indicative eye lens dose of 1.47 mSv per procedure was found. For the radiographic procedures, conducted using digital facilities, patient doses for the chest, and for abdomen and pelvis procedures, ranged from 0.1 mSv to 0.5 mSv. Patient radiogenic risk per procedure ranged from 10-5 to 10-4. Patient doses were seen to be comparable with values reported in previous studies, also showing wide variation, in general attributable to differences in exposure settings and scan length (for the CT study). The study also showed some 65% of the CT procedures to accord with typical findings. [1] Sulieman, A. (2016). Appl. Radiat. Isot. 117: 65-69. [2] Sulieman, A. (2008). Br. J . Radiol. 80: 731-737. [3] ICRP 103. (2007). Elsevier. ICRP Publication. Keywords: Radiation risk; Radiology; Dosimetry; Pediatric imaging 26 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Estimation of the effectiveness ratio () for resistant cancer stem cells in U87MG human glioblastoma Perla Marmolejo-Leóna,b, Erika Azorín-Vegaa*, Héctor Javier Mendoza-Navaa, Eleni Mitsoura and Eugenio Torres-García Email; [email protected] a Gerencia de Aplicaciones Nucleares en la Salud, Instituto Nacional de Investigaciones Nucleares Ocoyoacac, Estado de México 52750, México b Facultad de Medicina, Universidad Autónoma del Estado de México Toluca, Estado de México 50120, México Abstract Glioblastoma (GBM) contains self-renewing, tumorigenic cancer stem cells (CSCs) that contribute to tumor initiation and therapeutic resistance. The  and  parameters of the linear-quadratic model are very valuable to understand the radiation response of cells. The aim of the present study was to estimate and compare the effectiveness ratio (/) of stem cells and differentiated glioma cells derived of U87MG cell line to understand the radiobiology of the radioresistance of GBM stem subpopulations. Cell survival experiments were performed using a radiation dose rate of 227.68 mGy/min delivered by a 60Co source within a dose range of (0-16 Gy) as an accelerated hyperfractionation scheme. Biochemical characterization of post-irradiated cells was performed by flow cytometry analysis. To calculate the percentage of stem cells that resisted irradiation, the expression of immature markers (CD133) were detected. The molecular mechanisms by which stem cells resist radiation treatment the state of key proteins for proliferation and apoptosis were also evaluated. Keywords: Cancer stem cells; Glioblastoma; Linear quadratic model; Survival curves. 27 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Water-equivalence of gel dosimeters for radiology medical imaging M. Valente1,2,3,*, J. Vedelago1,2, D. Chacón2,4, F. Mattea2,5, P. Pérez1,2 1 2 Instituto de Física E. Gaviola - CONICET, Av. M. Allende s/n, Córdoba, Argentina. Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Universidad Nacional de Córdoba, Av. M. Allende s/n, Argentina. 3 Centro de Física e Ingeniería en Medicina - CFIM & Departamento de Ciencias Físicas, Universidad de La Frontera, Francisco Salazar 1145, Temuco, Chile. 4 Departamento de Física, Universidad Nacional, Heredia, Costa Rica. 5 Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, CONICET, Córdoba, Argentina. * Email: [email protected] Abstract Dosimetric protocols are based on determinations of absorbed dose in reference conditions defining specific measurement depth (zmax) in a homogeneous water phantom. Quality assurance should be performed in water-equivalent media, i.e. materials presenting the same absorption and scattering properties as water for the involved radiation. However, practical clinical situations involve inhomogeneities within the phantom or directly due to the employed dosimeter itself, thus requiring suitable conversions to link the readout with in-water absorbed dose, as required by protocols. This process incorporates intrinsic uncertainties in the corresponding calibration factors. Therefore, dosimetry systems directly based on in-water measurements are the only reliable option to overcome these drawbacks. Gel dosimeters (Fricke and polymers) appear as the most suitable option to design dosimeters capable of performing direct measurements of absorbed dose in aqueous media acting as sensitive material in the detection system. Although water-equivalence for some gel dosimeters at radiotherapy energy ranges was already investigated, there is a lack of studies reporting physical and radiological properties of different gel dosimeter types at low energies for radiology imaging. This study reports on theory and Monte Carlo approach aimed at characterizing physical and radiological parameters affecting water-equivalence properties of gel dosimeters at low (130 keV) energies typical for imaging radiology. Moreover, theoretical predictions for different gel dosimeter formulations (Fricke, PAGAT, NIPAM, and ITABIS) were successfully benchmarked by direct experimental measurements of radiological properties performed by the high resolution micro-Computed Tomography facility at the X-ray imaging line at LIIFAMIRX, confirming overall waterequivalence for all gel dosimeters presenting variations with respect to water in the low energy radiology range less than 3% in average. Keywords: Gel dosimetry water-equivalence; Monte Carlo simulations; Computed tomoghraphy. 28 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Geometric study of Astrocytomas with fractal analysis Francisco Torres–Hoyos1,*, Rubén Baena Navarro2, Juan Vergara Villadiego2 1 Department of Physics, University of Córdoba, Colombia Department of System Engineering, University Cooperativa de Colombia, Colombia 2 Department of System Engineering, University Cooperative of Colombia, Colombia 3 Department of System Engineering, University Cooperative of Colombia, Colombia * Email: franciscotorreshoyos@ gmail.com Abstract Tumor growth can be characterized by using scaling analysis methods performed upon the tumor interface; the procedure yields key parameters that define growth geometry according different universality classes. In the present work, results obtained by scaling analysis are shown for tumor astrocytomas, of primary origin, i.e, pilocytic, diffuse and anaplastic, is used to calculate fractal dimension and local roughness exponents to characterize in vivo 3-D tumor growth. Image acquisition was made according to the standard protocol used for brain radiotherapy and radiosurgery, i.e., axial, coronal and sagittal magnetic resonance T1-weighted images, and comprising the brain volume for image registration. Image segmentation was performed by the application of the k-means procedure upon contrasted images. For this it is identified, in the image, the area it corresponds completely to the tumor, giving so the exact limits where the functions following must carry out your corresponding operations. One time the images have been binarized, according to the K- means method, it is applied on the objects of interest a combination of morphological operators of erosion and dilation, those which permit eliminate small structures and fill up or close present hollows in the volume of interest. In order to obtain the points of the belonging surface to the tumor interface-host, an algorism was developed, of way such that preserves so much the classification of the voxels, according to the k- means method, as also the geometric characteristics in the interface. Keywords: Astrocytomas; Fractal dimension; Tumor growth; Scaling analysis. 29 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Protocol optimization in chest CT scans of newborn Luana Tavares Abrão Lima1, Fernando Amaral de Oliveira1, Wanderley dos Santos Roberto and Arnaldo Prata Mourão1,2 1 Centro Federal de Educação Tecnológica de Minas Gerais Centro de Engenharia Biomédica Av. Amazonas CEP 30421-169 Belo Horizonte, MG, Brasil 2 Universidade Federal de Minas Gerais Departamento de Engenharia Nuclear, Escola de Engenharia Av. Antônio Carlos CEP 131270-901 Belo Horizonte, MG, Brasil Email: [email protected] Abstract The use dissemination of Computed Tomography (CT), a radiodiagnostic technique, has significant increase in the patient dose. In the last years, this technique has shown a high growth due to clinical cases of medical emergencies, neoplasm and pediatric traumas. Dose measurement is important to correlate with the deleterious effects of radiation on the organism and radiation future effects is related with stochastic risks due to tissue radiosensitivity allied to the life expectancy of the child. In this work, a cylindrical phantom, representing an adult chest made of polymethylmethacrylate (PMMA), was used and a new born chest phantom with a shape oblong was developed based on the dimensions of a typical newborn. In a GE CT scanner, Discovery model, with 64 channels, the central slice of the phantoms were irradiated successively in order to obtain dose measurements using an ionizing pencil camera. Based in the measurements, dose index was calculated on PMMA (CTDIvol). The radiological service chest protocol using a voltage of 120 kV was used for scanning 10 cm of the central area of the adult and newborn phantom, in helical mode. An acquisition of images was performed using this radiological service chest protocol to compare with the protocol optimized. In the newborn phantom was also used protocols optimized using a voltage of 120, 100 and 80 kV. The voltage of 80 kV had the lowest dose index for the pediatric object. This work allowed the comparison between dose variations absorbed by the pediatric phantom changing the X-ray tube supply voltage. This dose variation has shown how important is specific protocols for children. Keywords: Pediatric; Dose profile; Computed tomography 30 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Evaluación del riesgo crónico por uso de radiación en personal ocupacionalmente expuesto (POE) en el área de la salud oral Corina Flores Hernández1, María Raquel Huerta Franco1 Modesto Antonio Sosa Aquino 2, Luz Verónica Díaz de León Morales3 1 Laboratorio de Salud Ocupacional e Higiene Ambiental Departamento de Ciencias Aplicadas al Trabajo, División de Ciencias de la Salud Universidad de Guanajuato, C.P 36320 León, Gto., México. 2 Departamento de Ingeniería Física, División de Ciencias e Ingenierías Universidad de Guanajuato, C.P 37150 León, Gto., México. 3 Dirección de Educación e Investigación en Salud UMAE No. 48, León Gto., México. Buzones electrónicos: [email protected]; [email protected] Resumen Existe una discordancia científica en las cantidades de radiación usadas en radiodiagnóstico y recibidas en la práctica por el personal ocupacionalmente expuesto (POE), a excepción de radiólogos que siguen las medidas de seguridad e higiene recomendadas por la normatividad. El objetivo de este estudio fue cuantificar el riesgo del POE en el área odontológica por la utilización de radiación ionizante crónicamente. Una variable fundamental a tomar en cuenta en el estudio fue el número de películas tomadas día/turno. Se llevó a cabo un estudio comparativo, n = 70 sujetos de estudio. Se realizó la recolección de información por historia clínica ocupacional, monitoreo biológico y ocupacional. La media de edad fue de 19.6 años para el Ẽ y del E fue de 50 años. La emisión de radiación en los equipos calibrados fue de 1.578( LP). El riesgo es 2:1 Ẹ:Ẽ. Se encontró en el estudio que en la mayoría de los casos el POE no utiliza medidas de protección, solamente el paciente. Palabras clave: Exposición; Radiación ionizante; POE; Dosis. 31 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Microcalcification evaluation using CR plates in computerized mammography Mabel Bustos Flores1 and Arnaldo Prata Mourão1,2 ¹Federal University of Minas Gerais Department of Nuclear Engineering, School of Engineering Av. Antônio Carlos CEP 131270-901 Belo Horizonte, MG, Brazil ²Federal Center for Technological Education of Minas Gerais Center for Biomedical Engineering Av. Amazonas CEP 30421-169 Belo Horizonte, MG, Brazil Email: [email protected] Abstract Cancer is one of the leading causes of mortality in the world. In 2012, about 14 million new cases were registered, of which 1.6 million are breast cancer, according to the World Health Organization. The National Cancer Institute of Brazil estimated 57 thousand new cases of breast cancer by 2016. Mammography is the imaging technique most used worldwide for the early diagnosis of breast cancer. Computed radiography plates (CR) are used for digital radiography, and are widely used to obtain digital mammograms. This work aims to evaluate the response of CR plates to the variation of exposure in mammography equipment. Three CR plates for mammography of different models were used for the study. X-ray beams were selected to perform successive exposures of CR plates by varying the exposure time. These exposures were performed to obtain raw images that were subsequently analyzed using ImageJ software, from which the value of intensity recorded in the central region of each image was obtained, correlating it with the exposure time. From these data the necessary correlations were made to determine the exposure time for which the CR plate begins to saturate, observing that the saturation occurs first for the highest value of the applied voltage. Finally, successive exposures of the CR plate were made using the compressed breast simulator made of acrylic plates and containing microcalcifications of different sizes to determine the qualitative resolution of CR plates, observing that only microcalcifications above 177 m are visible in the image. The knowledge of saturation characteristics and resolution of the CR plate allows the selection of more adequate parameters to work without approaching the saturation region. Keywords: Computed radiography; Mammography and medical images. 32 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Comparative dosimetric study using pediatric phantom in chest computed tomography scans Wadia Namen Aburjaile1, Gislene Guedes2 and Arnaldo Prata Mourão1,2 1 Department of Nuclear Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627, CEP: 31270-90, Pampulha, Belo Horizonte, MG, Brazil 2 Biomedical Engineering Center, Federal Center for Technological Education of Minas Gerais, Av. Amazonas, 5253 - Sala 113. CEP: 30421-169, Nova Suíça, Belo Horizonte, MG, Brazil Email: [email protected] Abstract The dissemination of Computed Tomography (CT) tests have promoted a significant increase in the absorbed dose by patients due to the diagnosis. Therefore, it is indispensable to improve protocols, seeking smaller doses, without impairing the diagnostic quality of the image[1,2]. The risks of stochastic effects are greater for children due to tissue radiosensitivity coupled with longer life expectancy[3]. In this work, a cylindrical phantom was used, representing an adult chest made of polymethylmethacrylate, and a second phantom of the same material was designed in an oblong shape, including axillary region, based on the dimensions of the pediatric patient's thorax with 8 years old. A comparative study was performed observing chest scans in two CT scanners of different radiodiagnostic services. The central slice of the two phantoms was irradiated successively, using a pencil ionization chamber, for the measurements in five different points of each simulating object. From the measurements, it was obtained values of weighted and volumetric Dose Index (CK,PMMA,vol) for scan of 10 cm length of the phantom central region, in helical mode. The scans were performed with chest acquisition protocols used in the radiodiagnostic services, both for a 120 kV X-ray tube supply voltage. This work allowed compare the absorbed dose between patients with variable chest volumes and the dose variation in patients in two CT scanners used for image generation with the same diagnostic objective. [1] American Association of Physicists in Medice (2010). Comprehensive Methodology for the Evaluation of Radiation Dose in X-Ray Computed Tomography (Report #111). College Park, MD. (implemented by TG-200). [2] Burgener F; Kormano M. Differential Diagnosis in Computed Tomography. CINAMON, Jay. Marconi multislice spiral CT principles & applications, Atlanta, 2001. 61p. [3] Kleinman PL et al. Patient size measured on CT images as a function of age at a tertiary care children’s hospital. AJR Am J Roentgenol. 2010; 194(6):1611-1619, Thieme, 2a. edição, 2012; Keywords: Computed Tomography, phantoms, dosimetry. 33 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Diseño y desarrollo de un sistema de localización de vasos sanguíneos mediante Visor NIR Angélica Hernández Rayas 1,*, Luis Emmanuel Plascencia Cruz1, Teodoro Córdova Fraga1, Nicolás Padilla Raigoza2 1 2 Universidad de Guanajuato, 37150 León Gto., México Universidad de Guanajuato, 38140, Celaya-Salvatierra Gto., México * Email: [email protected] Abstract Además de las múltiples aplicaciones de la radiación ionizantes en el diagnóstico clínico existe la posibilidad de emplear otra parte del espectro electromagnético tal como el infrarrojo cercano (NIR). En este trabajo se presenta el diseñó y la construcción un Biosensor de NIR en un rango entre 800 y 900 nm, el cual permite la visualización de vasos sanguíneos para el procedimiento de venopunción con el objetivo de reducir el trauma del acceso venoso a los pacientes de todas las edades. También se explora la posibilidad de que el dispositivo sea empleado en la ubicación de úlceras venosas como alternativa a los venogramas obtenidos mediante rayos X. Palabras clave: Visor NIR; Venas; Acceso venoso; Infrarrojo cercano; Biosensor. 34 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Pruebas de hipótesis estadísticas en la respuesta de la proliferación de un cultivo de Saccharomyces cerevisiae con variación en los parámetros del campo magnético aplicado Erandeni Xuxumarat Rodríguez Pérez1, Verónica A Mondragón Jaimes2, Mario Guerrero Rodriguez2, Benjamín Hernandez Reyes1, Modesto A Sosa Aquino1 1 2 Universidad de Guanajuato Universidad Autónoma de Nayarit Buzón-e: [email protected] Resumen En las últimas décadas, el estudio de los efectos del campo magnético en los sistemas biológicos ha aumentado, siendo la Saccharomyces cerevisiae el modelo biológico más estudiado. A lo largo de los años, se han realizado muchos estudios para comprender el efecto del campo magnético sobre la proliferación de S. cerevisiae, sin embargo los resultados han sido polémicos. Todos ellos se han hecho con tiempos de exposición diferentes, diferentes equipos generadores de campo magnético y distinta intensidad del campo magnético. Por lo tanto, este estudio pretende evaluar cambios en la proliferación al exponer a campos magnéticos, de baja frecuencia y corrientes distintas, cultivos de Saccharomyces cerevisiae. Los campos magnéticos sinusoidales fueron generados por un par de bobinas de Helmholtz. Los campos magnéticos se aplicaron con frecuencias diferentes de 20 Hz a 192.5 Hz y la intensidad de la corriente estaba en el intervalo de 1 a 3 A. El cultivo experimental se expuso a campos magnéticos durante 12 horas. El monitoreo del crecimiento se realiza durante la exposición midiendo la densidad óptica a = 600nm, cada 30 min. Los resultados encontrados muestran que el cambio en la frecuencia es el parámetro más importante en la proliferación celular (p > 0.05%), mucho mayor que la intensidad del campo magnético. Se encuentra además una dependencia en el modelo matemático empleado en la descripción de los datos experimentales. Palabras clave: Campo magnético, frecuencia, proliferación, Saccharomyces cerevisiae. 35 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Análisis de Plutonio-239 en personal ocupacionalmente expuesto Héctor Hernández-Mendoza Universidad del Centro de México, San Luis Potosí, SLP. Capitán Caldera, 75, Colonia Tequixquiapan, 78250 San Luis, SLP. Buzón-e: [email protected] Abstract A parte de las técnicas radiométricas, se pueden utilizar varías técnicas de Espectrometría de Masas (MS) para evaluar la incorporación del Plutonio-239 (239Pu) en el Personal Ocupacionalmente Expuesto (POE), entre las técnicas de MS, podemos considerar Espectrometría de Masas de con Fuente de Plasma Acoplado Inductivamente (ICP-MS), Espectrometría de Masas con Aceleradores (AMS), Espectrometría de Masas de Ionización Térmica (TIMS), Espectrometría de Masas de Iones Secundarios (SIMS) y Análisis de Trazas de Fisión (FTA). En este trabajo fueron evaluaron métodos analíticos para medir isótopos de 239Pu en muestras de orina procedentes de POE usando Espectroscopia Alfa (AS), Espectrometría de Masas de Sector Magnético con Fuente de Plasma Acoplado Inductivamente (ICP-SFMS) y Espectrometría de Masas con Aceleradores (AMS). Las muestras fueron colectadas durante 24 h y fueron acidificadas con HNO3 al 5% en v/v. Los procesos usados en la preparación de las muestras fueron; a) co-precipitación, b) digestión ácida, c) separación radioquímica y d) electrodeposición. Los resultados obtenidos en términos de Actividad Mínima Detectable (AMD) de 239Pu fueron de 0.1 µBq (~ 0.4 fg por muestra), 4.6 µBq (~ 2 fg por muestra) y 0.2 mBq (~ 90 fg por muestra) para AMS, AridusICP-SFMS y AS, respectivamente. Por otra parte, muestras previamente analizadas por AS fueron re-evaluadas por ICP-SFMS, Aridus-ICP-SFMS y AMS. Los resultados muestras que la extracción con 60 mL de HNO3 al 5% a 60 °C y durante 3 h es suficiente para extraer el 90% de Pu electrodepositado en la plancheta. En conclusión, AMS es una técnica ultra sensible para determinar relaciones isotópicas de Pu, en especial cuando se quiere validar un método para medir 239Pu, además ICP-SFMS es una técnicas de análisis rápido, la cual puede ser usada como técnica de screening en situaciones de incidentes o accidentes radiológicos con Pu en los POE. En el caso AS se ha considerado como la técnica de excelencia en el análisis de rutina para medir 239Pu en POE, debido al bajo costo. Además, cabe mencionar que AS abre la posibilidad a la re-evaluación de las muestras de baja actividad que se encuentra por debajo de AMD usando ICP-SFMS y AMS. Keywords: Orina; Plutonio-239; AS; ICP-SFMS; AMS. 36 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Presencia de micronúcleos en personal médico y asistentes en centros de radiología en México Modesto Antonio Sosa1,*, Nicolás Padilla2, Vicente Beltrán2, Silvia del Carmen Delgado2, María de Lourdes García2, Rebeca Monroy3, Miguel Ángel Vallejo1 1 Universidad de Guanajuato, División de Ciencias e Ingenierías Loma del Bosque 103, Colonia Lomas del Campestre, 37150 León, Gto., México 2 Universidad de Guanajuato, Campus Celaya Salvatierra División de Ciencias de la Salud e Ingenierías, Mutualismo 303, 38060 Celaya, Gto., México 3 Universidad de Guanajuato, División de Ciencias de la Salud Departamento de Medicina y Nutrición, León, Gto., México Buzón electrónico: [email protected] Resumen El objetivo de este estudio fue determinar la presencia de micronúcleos en células de la mucosa oral en personas expuestas a radiación ionizante y utilizarlas como marcadores de daño genético por radiación crónica. Se realizó un estudio transversal comparativo en médicos, personal de enfermería y asistentes en centros de radiología de Celaya, México, en comparación con médicos, enfermeros y asistentes que no trabajan con radiaciones ionizantes. Se cepilló la mucosa oral y se cuantificó la cantidad de micronúcleos. Se calculó una t-student para dos medias independientes para la presencia de micronúcleos en individuos expuestos y no expuestos. Se calculó Chi cuadrada, Razón de Momios y Fracción Atribuible para determinar la correlación entre estar expuesto a radiación ionizante y tener daño genético. La muestra consistió de 30 personas expuestas y 30 personas no expuestas. El grupo expuesto tuvo un promedio de micronúcleos de 5.37 ± 3.49 y el grupo no expuesto de 0.37 ± 0.61 (t = 7.73, dof = 58, p = 0.00001). En el grupo expuesto se encontró un 90% de participantes con daño genético y un 6.67% en los no expuestos (χ2 = 41.71, dof = 1, p = 0.0001, OR = 126, 95%CI de 19.50 a 813.98, AFExp = 99.21%). El estudio permite concluir la presencia de daño genético en el personal médico y los asistentes de radiología expuestos a radiación ionizante a largo plazo en centros de radiología en Celaya, México. 37 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Inversion recovery sequences improve delineation of optic pathways in the proximity of suprasellar lesions Herwin Speckter, José Bido, Giancarlo Hernandez, Luis Suazo, Diones Rivera, Santiago Valenzuela, Peter Stoeter Dominican Gamma Knife Center, CEDIMAT Santo Domingo, Dominican Republic Email: [email protected] Abstract About 10,000 patients receive Gamma Knife Radiosurgery GKRS every year in order to treat suprasellar lesions. Exact localization of the visual pathways is important to avoid radiogenic damage to the optic system, but reliable identification of the optic nerve, chiasm and tracts, can be challenging using routine magnetic resonance imaging. This study investigates the application of inversion recovery sequences (Fast gray and white matter acquisition T1 inversion recovery, FGATIR) to either suppress the signal of these structures or to suppress the signal of its surroundings. Inversion recovery sequences were performed on 5 healthy volunteers, varying their inversion times between 400 and 500 ms, as well as between 800 and 1100 ms. Inversion times were optimized to either suppress or to preserve the signal of the optic structures, while increasing or suppressing the signal of processes within the surrounding cisterns. Varieties of inversion recovery sequences were performed before radiosurgery on 10 patients with suprasellar tumors that were compressing or displacing the optic structures. Signal intensities of gray and white matter, of CSF and tumors were measured and subtraction images were calculated. Compared to a standard T1weighted sequence, delineation of the visual pathways was superior on inversion recovery images, both on images with suppression of the structures as well on images with suppression of its surroundings, and was rated best on subtraction images. For radiosurgery of suprasellar tumors displacing optical structures, inversion recovery sequences can be of valuable benefit for exact delineation and dose planning of the optic system, in order to avoid possible radiogenic damage. [1].- Speckter H et al., (2016). J Neurosurg 125: 83–88. Keywords: Gamma knife radiosurgery; Diffusion tensor imaging; Meningioma. 38 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Diffusion tensor imaging parameters predict response of meningiomas to radiosurgery Herwin Speckter, José Bido, Giancarlo Hernandez, Luis Suazo, Diones Rivera, Santiago Valenzuela, Peter Stoeter Dominican Gamma Knife Center, CEDIMAT Santo Domingo, Dominican Republic Email: [email protected] Abstract Subtypes of WHO grade I meningiomas are difficult to distinguish with conventional magnetic resonance imaging. Control rates in meningiomas after Gamma Knife Stereotactic Radiosurgery (GKRS) are high; however there are about 7.5 % of meningiomas which continue to grow. A superior control rate may be achieved if there would be a possibility to predict the meningioma subtype without intervention and to adjust prescription dose accordingly. Diffusion Tensor Imaging (DTI) parameters are able to differentiate between meningioma subtypes, based on their fibrous tissue concentration. We tested the hypothesis that there is a correlation between DTI parameters and the change of tumor volume after GKRS, expecting that fibrous-rich tissue has lower radiosensitivity. DTI parameters were measured by Magnetic Resonance Imaging (3T Achieva Philips) before GKRS in 34 patients with meningiomas. After GKRS treatment with a prescription dose of 11 to 18 (mean: 13.9±1.7) Gy, the tumor volume was followed over more than 12 month, up to 43 months (average: 27.9 months). Only those meningiomas showing the highest Fractional Anisotropy (FA), the lowest Spherical Index (Cs) and the lowest Radial Diffusibility (RD) increased or remained stable in volume, whereas all others decreased. The correlation between DTI parameters (FA: -0.78, Cs: 0.71, RD: 0.66) and volume change rate was significant (p<0.001). Other factors, including original tumor size, prescription dose and patient’s age, do not correlate significantly. Meningiomas showing high FA, as well as low Cs and low RD are less susceptible to GKRS. This finding might be due to their higher content of fibrous tissue. In order to improve the control rate of meningiomas showing high FA we propose to increase the prescription dose, furthermore complication rate may be decreased by reducing dose to well responding meningiomas. [1].- Speckter H. (2016). J Neurosurg 125: 83–88. Keywords: Gamma Knife Radiosurgery; Diffusion Tensor Imaging; Meningioma. 39 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Hipertermia generado por corrientes Foucault para tratamientos oncológicos con COMSOL Romero Coripuna R L1, *, Cordova Fraga T1, Basurto Islas G1 y Guzmán Cabrera R2 1 Departamento de Ingeniería Física-DCI, Universidad de Guanajuato Campus León Loma del Bosque N. 103, Lomas del Campestre, 37150 León, GTO, Mex. 2 Division de Ingenierías, Universidad de Guanajuato, Campus Irapuato-Salamanca Salamanca-Valle de Santiago Km 3.5+1.8 Km, Palo Blanco, 36885 Salamanca, GTO, Mex. * Buzón-e: [email protected] Resumen La hipertermia generada por campos magnéticos variables es una propuesta prometedora para el tratamiento del cáncer ya que las células cancerígenas mueren por apoptosis a temperaturas comprendidas entre 42 °C y 45 °C, se sabe que existen 3 mecanismos físicos capaces de generar calentamiento al emplear campo electromagnético alternos usando las nanopartículas de Fe3O4: Las generadas por corrientes Foucault, perdidas en los ciclos de histéresis y perdidas por relajación, por lo tanto aprovechando las pérdidas de energía a través del efecto joule y la transformación en calor, se describe la distribución temporal de la temperatura en sistemas biológicos transformados, con el objeto de tener mayor conocimiento de estas propiedades y avanzar en los estudios relacionados con la hipertermia magnética. Palabras clave: Hipertermia; Corrientes Foucault; Cáncer; COMSOL. 40 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Determinación de la distribución espacial de dosis en tratamientos de CACU con braquiterapia LDR usando métodos Monte Carlo Jorge Luis Benites-Rengifo1 & Héctor René Vega-Carrillo2 1 Centro Estatal de Cancerología de los Servicios de Salud de Nayarit Tepic-Nayarit, México 2 Universidad Autónoma de Zacatecas/Unidad Académica de Estudios Nucleares Zacatecas, México Buzón-e: [email protected] Resumen Usando métodos Monte Carlo, con el código MCNP5, se determinó la distribución espacial de la dosis absorbida en tratamientos de cáncer cérvico uterino (CACU) bajo la modalidad de braquiterapia de baja tasa de dosis (LDR). Mediante el código se modeló la región ginecológica como un paralelepípedo de 50 x 30 x 30 cm3, en el cual se insertaron cuatro unidades de acrílico, formando un cilindro vaginal de 10.5 cm de largo y 2 cm de diámetro que se montó sobre un tubo de acero inoxidable de 16 cm de largo por 0.6 cm de diámetro. En el tubo se insertó un arreglo lineal de cuatro fuentes selladas de Cs-137, emisores de rayos gamma con energía de 662 keV. Los resultados Monte Carlo de la dosis se escalaron a los fotones emitidos por 4 fuentes reales de Cs-137 de 50, 50, 50, 37.5 mCi. En un tratamiento ginecológico el tumor debe recibir una dosis total de 30 Gy, normalmente indicada por el médico tratante en un protocolo de LDR. En los cálculos también se estimaron los valores del Kerma en aire de cada una de las fuentes selladas de Cs-137. La cantidad de historias que se usaron permitió obtener una incertidumbre relativa menor al 5%. Palabras clave: Braquiterapia; CACU; LDR; MCNP; Monte Carlo. 41 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Staff and ambient radiation dose in therapeutic nuclear medicine procedures Mohammed Alkhorayef1,2*, Abdelmoneim Sulieman3, Huda Al-Mohammed4, Naser Alkhomashi5, David Bradley,2,6 1 Radiological Sciences, College of Applied Medical Sciences King Saud University, PO Box 10219, Riyadh 11433, Saudi Arabia 2 Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, UK. 3 Prince Sattam Bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, Saudi Arabia 4 Department of Medical Technical, College of Health and Rehabilitation Sciences, Princess Nora Bint Abdulrahman University, PO Box 84428, Riyadh 11671, Saudi Arabia 5 King Abdulaziz City for Science and Technology (KACST) P.O. Box 6086, Riyadh 11442, Saudi Arabia 6 Sunway University, Institute for Health Care Development Jalan University, 46150 PJ, Malaysia * Email: [email protected] Abstract The use of I–131 for treatment of benign and malignant thyroid disease is common practice worldwide. Radioactive iodine (RAI) therapy, a targeted treatment, improves the survival rate of patients with thyroid cancer, with cure rates in excess of 90 %. During treatment the patient becomes a source of relatively high energy γ-radiation to then be considered a potential radiation source of exposure for staff, family members and the environment The objectives of this study were to evaluate the radiation exposure from patients thus treated, during their period of hospitalization and to estimate staff accumulated dose and related risk during preparation of the I-131. A total of 34 patients were investigated (21 females and 13 males). Radiation exposures to hospital personnel attending these patients were calculated as a function of administered dose distance from the patient and at different times after the administration. A calibrated ionization chamber and thermoluminescent dosimeters (TLDs, GR200A)) were used to measure the ambient dose and staff dose, respectively. The patients received sodium Iodide I-131 capsules with activities at the time of calibration ranging from 37 to 4810 MBq. The radiation dose was measured on three consecutive days after the administration. Data were collected to investigate the rate of iodine decay per days of hospitalization. The mean and range of patient age (in years), weight (in kg) and body mass index (BMI) were respectively 37.5 ± 15.3 (20 - 73), 68.1 ± 11.2, (47 - 93), 25.0 ± 4.9, (20.0 - 39.7). Staff annual doses ranged between 2.1- to 4.2 mSv, below the annual dose limits in respect of current practice and workload. [1] Pandit and Vinjamuri (2014). Indian J Nucl Med. 29(3): 131–134. [2] Hamza, Y. (2015). Radiat Prot Dosim. 165 (1-4): 452-456. Keywords: Iodine 131; Occupational exposure; Dosimetry; Nuclear Medicine 42 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Determinación de la dosis en cristalino y tiroides durante el examen de tomografía de tórax con MCNP Basilia Quispe Huillcara*. 1, José Domingo Peña Vidal 1, Georgina Waldo Benítez1, Manuel León Madrid1, Pablo Cerón Ramírez 1, Miguel Ángel Vallejo Hernández1, Modesto Sosa Aquino1, Héctor René Vega-Carrillo 2 1 División de Ciencias e Ingenierías de la Universidad de Guanajuato Loma del Bosque #103, Lomas del Campestre, C.P. 37150. León, Gto., México. 2 Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas Ciprés #10, Fraccionamiento La Peñuela, 98060 Zacatecas, México *Buzón-e: [email protected] Resumen La Tomografía Computarizada(TC) es un método de diagnóstico por imágenes que genera dosis más altas que otros métodos de radiodiagnóstico, basada en la atenuación de los rayos X. El conocimiento del espectro de los rayos X es importante, ya que está en función directa con la dosis absorbida por el paciente. En este trabajo se estimó el espectro de los rayos X, producidos durante la interacción de electrones monoenergéticos de 130 keV con blanco de Tungsteno, con la finalidad de determinar sus características energéticas y la dosis equivalente ambiental a 50 cm del punto focal. El estudio se hizo mediante métodos Monte Carlo con el código MCNP5 donde se modeló el tubo de rayos X de un tomógrafo Siemens SOMATOM Perspective del Hospital General Regional de León México. El espectro calculado muestra una componente continua y otra discreta, la parte continua se comparó con el espectro calculado con el código SpekCalc con RMS de 0.44, mientras que la parte discreta se comparó con el espectro del NIST. E los cálculos se usaron 3x108 historias y se obtuvo una incertidumbre relativa menor al 0.1%. También se modeló un maniquí de cabeza, cuello y tronco que incluyó el ojo humano, la glándula tiroides, la mesa y gantry con apertura de 70 cm del tomógrafo. Como termino fuente se usó el espectro de los rayos X calculado y se usó un campo de 6x20 mm. El protocolo de exploración de rutina del servicio radiológico fue utilizado para la TC de tórax, el método paso a paso o disparo instantáneo fue simulado moviendo las coordenadas del maniquí para cada corte. Palabras clave: Espectros de Rayos X; Monte Carlo; MCNP5; Tomógrafo; Dosis. 43 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Quality control in dual head γ- cameras: Comparison between methods and softwares used for image analysis Abdalrhman Nayl Edam 1,*, Maria Rosa Fornasier 2, Mario de Denaro 2 Abdelmoneim Sulieman 3, Mohammed Alkhorayef 4,5, David Bradley 5,6 1 Radiation Safety Institute, Sudan Atomic Energy Commission, Khartoum, Sudan Medical Physics Department, Azienda Sanitaria Universitaria Integrata Trieste (ASUITS), Italy 3 Radiology and Medical Imaging Department, Prince Sattam Bin Abdulaziz University College of Applied Medical Sciences,Saudi Arabia 4 Department of Radiological Sciences, College of Applied Medical Sciences King Saud University, PO Box 10219, Riyadh 11433, Saudi Arabia 5 Department of Physics, University of Surrey, Guildford, Surrey, UK 6 Sunway University, Institute for Health Care Development, Jalan University, 46150 PJ, Malaysia 2 * Email: [email protected] Abstract Patient radiation dose and image quality are the main issues in nuclear medicine (NM) procedures. Currently, many protocols are used for image acquisition and analysis of quality control QC tests. National Electrical Manufacturers Association (NEMA) methods and protocols are widely accepted method used for providing accurate description, measurement and reporting of γ-camera performance parameters. However, no standard software is available for image analysis. The aim of this study was to compare between the vendor QC software analysis and three software from different developers downloaded free from internet; NMQC, NM Toolkit and imageJ-NM Toolkit software. The three software are used for image analysis of some QC tests for γ-cameras based on NEMA protocols including non-uniformity evaluation. Ten non-uniformity QC images were taken from dual head γ-camera (Siemens Symbia) installed in Trieste general hospital (Italy), and analyzed. Excel analysis was used as baseline calculation of the non-uniformity test according NEMA procedures. The results of the non-uniformity analysis showed good agreement between the three independent software and excel calculation (the average differences were 0.3%, 2.9%, 1.3% and 1.6% for UFOV integral, UFOV differential, CFOV integral and CFOV differential respectively), while significant difference was detected on the analysis of the company QC software with compare to the excel analysis (the average differences were 14.6%, 20.7%, 25.7% and 31.9% for UFOV integral, UFOV differential, CFOV integral and CFOV differential respectively). NMQC software was the best in comparison with the excel calculations. The variation in the results is due to different pixel sizes used for analysis in the three software and the γ- camera QC software. Therefore, it is important to perform the tests by the vendor QC software as well as by independent analysis to understand the differences between the values. Moreover, the medical physicist should know the pixel sizes used in each; the independent software and company QC software. The standard analysis software is needed to give the possibility to compare between the γ-camera systems in order to improve the image quality in NM imaging. [1] Quality Assurance for SPECT systems, IAEA human health series, No. 6, (2009). [2] Jeffrey S. Nelson et al., (2014). J Nucl Med., 55: 169–174. Keywords: Quality control; gamma camera; Nuclear Medicine; Image quality 44 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Analizador multicanal embebido en FPGA Ángel García Durán1*, Víctor M. Hernández Dávila1,3, Hector Rene Vega Carrillo1, Oscar O. Ordaz García2,3, Ignacio Bravo Muñoz4 1 Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas Zacatecas, Zac, México 2 Unidad Académica de Ingeniería Eléctrica, Universidad Autónoma de Zacatecas Zacatecas, Zac, México 3 Departamento de sistemas electrónicos, Universidad de Córdoba, Córdoba, España 4 Departamento de electrónica, Universidad de Alcalá, Alcalá de Henares, Madrid, España * Buzón-e: [email protected] Resumen Las diferentes aplicaciones de la radiación ionizante hace de esta, una herramienta muy significativa y útil, a su vez puede ser peligrosa para los seres vivos si son expuestos a dosis no controladas. Sin embargo, por sus características, no puede ser percibida por los cinco sentidos del ser humano, de tal manera que para conocer la presencia de esta se requieren de detectores de radiación y dispositivos adicionales que permitan cuantificarla y clasificarla. Este es el caso del analizador multicanal que se encarga de separar las diferentes alturas de pulso que se generan en los detectores, en un número determinado de canales; acorde al número de bits del convertidor análogo a digital. El desarrollo o acondicionamiento de tecnología nuclear ha aumentado considerablemente por la demanda de las aplicaciones, por consiguiente esto permite desarrollar sistemas que se adecuen a las necesidades del usuario, con características como reducción en el costo y volumen de los dispositivos. El objetivo del trabajo fue diseñar e implementar un núcleo de propiedad intelectual (IPcore) el cual funciona como un analizador multicanal para espectrometría nuclear. Los componentes del IPcore fueron creados en lenguaje de descripción de hardware VHDL y empaquetados en la suite de diseño Vivado, haciendo uso de los recursos como son el núcleo de procesamiento ARM que el chip Zynq contiene. Así mismo, para la primera fase de la implementación fue embebida en la FPGA la arquitectura hardware y programada en lenguaje C la aplicación para el procesador ARM. Para la segunda fase, el manejo, control y visualización de los resultados se desarrolló un instrumento virtual en la plataforma gráfica de programación LabVIEW. Los datos obtenidos como resultado del desarrollo e implementación del IPcore fueron observados gráficamente en un histograma que forma parte del instrumento virtual antes mencionado. Además los resultados obtenidos de los tres diferentes detectores de radiación (Centelleo, Germanio hiperpuro y Fotodiodo pin) con el analizador multicanal embebido en la FPGA, tienen una gran semejanza con los resultados de analizadores multicanal comerciales. Palabras clave: Multicanal; Espectrometría; ZYNQ; Vivado. 45 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Validación de métodos para medir isótopos de Uranio usando espectrometría de masas de sector magnético con fuente de plasma acoplado inductivamente Héctor Hernández-Mendoza1,*, María J Ríos-Lugo2, Elizabeth T Romero-Guzmán3 1 Universidad del Centro de México, San Luis Potosí, SLP. Capitán Caldera, 75, Colonia Tequixquiapan, 78250 San Luis, SLP. 2 Unidad de Posgrado, Facultad de Enfermería y Nutrición, Universidad Autónoma de San Luis Potosí, Avenida Niño Artillero 130, CP 78210, San Luis Potosí, S.L.P., México. 3 Departamento de Química, Gerencia de Ciencias Básicas-Tecnología Nuclear. Instituto Nacional de Investigaciones Nucleares. Carretera México-Toluca S/N km 36.5. C.P. 52750. A.P. 18-1027. La Marquesa Ocoyoacác México. *Buzón-e: [email protected] Resumen En este trabajo se muestra las capacidades analíticas para medir isótopos de Uranio (U) en el Laboratorio Nacional de Investigaciones en Forense Nuclear (LANAFONU). Los métodos validados han sido en agua, sedimentos, suelo y orina humana mediante ensayos de intercomparación realizados por el Organismo Internacional de Energía Atómica (OIEA) y Asociación para la Promoción del Control de Calidad de los Análisis de Biología Médica en Radiotoxicología (PROCORAD). Los isótopos de U que fueron medidos para la validación de los métodos usando Espectrometría de Masas de Sector Magnético con Fuente de Pasma Acoplado Inductivamente (ICP-SFMS) fueron; a) agua fuero medidos 234 U, 235U, 238U y U total, b) sedimento se midió U total, c) suelo se midieron 234U y 238U, y d) orina fue medido 238U. Para evaluar el rendimiento de los métodos, las muestras fueron trazadas con 242Pu como patrón interno. Los procedimientos empleados en el tratamiento de las muestras de suelo, sedimentos y agua fueron basados en métodos de US EPA (Agencia de protección medioambiental). En el caso de orina la preparación fue rápida (dilución 1:20). Los resultados obtenidos muestran recuperación de 242Pu fueron; 94%, 71%, 72% y 78% para las muestras de agua, orina, suelo y sedimento, respectivamente. La precisión en términos de Desviación Relativa Estándar (RSD) fue inferior al 5% y la exactitud acorde al valor de los Materiales de Referencia Certificado (CRM) fue inferior al 4%. En conclusión, el ICP-SFMS es una técnica muy sensible para medir isótopos de U en diferentes matrices. Sin embargo, es necesario realizar una sintonización minuciosa, especialmente en las regiones de masa de interés 234, 235 y 238 si se considera una cuantificación externa usando soluciones de U natural. Keywords: Uranio; ICP-SFMS; Agua; Suelo; Sedimento; Orina. 46 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Visualización de las partículas cargadas ionizantes Diego Cano Sánchez*, Luis Enrique Amarillas Saliá*, María Daniela Ortiz Allende*, Hector Rene Vega-Carrillo Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas C. Ciprés 10, Fracc. La Peñuela 98060 Zacatecas, Zac. México Buzón-e: [email protected] *Becari@s CONACyT Resumen El ser humano está expuesto a fuentes de radiación ionizante y no ionizante, ambas de origen natural o antropogénico. Ninguna de éstas, excepto la no ionizante como la luz visible y la radiación infrarroja, pueden ser detectadas por el sentido de la vista y del tacto respectivamente. El Sol emite partículas cargadas con velocidades cercanas a la luz que interactúan con los átomos de los gases presentes en la atmósfera produciendo reacciones nucleares que a su vez producen otras partículas que alcanzan la superficie de la Tierra y alcanzando a los seres vivos. En la Tierra existen radioisótopos naturales que al desintegrarse emiten radiación ionizante que contribuyen a la dosis que recibimos. Un sistema muy antiguo que permite la visualización de las trayectorias de las partículas cargadas ionizantes es la Cámara de niebla que usa un vapor saturado que al ser cruzado por partículas con masa y carga, como partículas alfa y beta producen centros de condensación a lo largo de su trayecto que deja una huella que se puede ver. El objetivo de este trabajo fue construir una cámara de niebla usando materiales de fácil acceso. Para probar el funcionamiento de la cámara se midieron los rayos cósmicos, así como una fuente de Uranio natural metálico. La cámara permitió ver la presencia de trazas en vapor de alcohol que se producen en forma aleatoria. Introduciendo la laminilla de Uranio dentro de la cámara permitió observar las trazas de las partículas alfa cuya energía varía de 4 a 5 MeV. Palabras clave: Cámara de niebla; Partículas cargadas; Radiación ionizantes. 47 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Caracterización Dosimétrica de KMgF3:Tb + PTFE Martha Itzel Ramírez-Romero1, Laura García-Salinas1, Maricela Villicaña-Méndez1, Rafael Huirache-Acuña1 , José Apolinar-Cortés1, Pedro R. González-Martínez2. 1. Facultad de Ingeniería Química, UMSNH Francisco J. Mújica S/N, Ciudad Universitaria Col. Felicitas del Río, C.P. 58030. Morelia, Mich., México. 2. Instituto Nacional de Investigaciones Nucleares (ININ) Carretera México-Toluca s/n. La Marquesa, Ocoyoacac. C.P. 52750, México. Buzones-e: [email protected], [email protected] Resumen En este trabajo se presentan los resultados obtenidos de la caracterización dosimétrica de los nuevos detectores de radiación de KMgF3:Tb+PTFE. La sal huésped se obtuvo mediante la técnica de microondas, con el polvo policristalino obtenido, se elaboraron dosímetros en forma de pastilla, usando como aglutinante PTFE. La respuesta termoluminiscente de estos nuevos detectores, presentó un comportamiento lineal, en el intervalo de dosis entre 1 y 1000 Gy de radiación gamma de 60Co, la prueba de reproducibilidad en las mediciones, durante diez ciclos de tratamiento térmico, irradiación y lectura, presentó ± 3.7 %DS, en la prueba de estabilidad de la señal termoluminiscente, durante dos meses mostró que el desvanecimiento es prácticamente nulo. Por los resultados obtenidos, este nuevo detector podría ser de mucha utilidad para la dosimetría de la radiación ionizante, en las diferentes aplicaciones clínicas. Palabras clave: Termoluminiscencia; Radiación ionizante; Dosimetría. 48 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Verificación dosimétrica en radioterapia conformal con un sistema de imágenes portales Benjamín Hernández-Reyes1,*, Xuxumarat Rodríguez-Pérez1, Modesto Sosa-Aquino1 1 División de Ciencias e Ingenierías de la Universidad de Guanajuato, campus León Loma del Bosque 103, 37150 León, Guanajuato, México. *Buzón-e: [email protected] Resumen La verificación dosimétrica en tratamientos de radioterapia es fundamental en el control de calidad. Diferentes métodos e instrumentos son utilizados para dicha verificación. Sin embargo, algunos son complejos y costos, o consumen mucho tiempo de trabajo. Actualmente los dispositivos de imagen portal electrónico (EPID, por sus siglas en inglés) se encuentran instalados en los aceleradores lineales y pueden ser utilizados para una verificación dosimétrica in vivo rápida. El objetivo del trabajo fue implementar el protocolo para cálculo y verificación de dosis in vivo bidimensional en campos conformales. Un linac Varian iX se utilizó con su EPID aS1000. Las mediciones fueron hechas para haces de 6 MV y 15MV. Se utilizó un maniquí de agua sólida (30×30×30 cm3) para verificar el protocolo. Para calcular la dosis con el EPID fue necesario medir su sensibilidad de los pixeles, la corrección fuera del eje, el kernel para corrección de dispersión del EPID, el kernel de dispersión del paciente y la retrodispersión del soporte del EPID para cada una de las energías. Las distribuciones de dosis del EPID se compararon con distribuciones calculadas por el sistema de planeación ECLIPSE®. Se comparó con pruebas de índice gamma la exactitud del protocolo establecido, se siguió el criterio de ΔD = 3% y Δd = 3 mm, y se encontró que más del 95% de los puntos evaluados tuvieron un valor γ menor que uno. El EPID demostró ser un dispositivo útil para una verificación dosimétrica rápida, ya que al estar instalado junto con el acelerador lo hace una herramienta fácil de utilizar durante los tratamientos. Palabras clave: EPID; Dosimetría; Acelerador Lineal; Radioterapia Conformal. 49 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Experimental evaluation of the 252Cf and 241Am-Be neutron sources of the Neutron Standards Laboratory of CIEMAT (Spain) Roberto Méndez1, Xandra Campo Blanco1, Francisco González Sánchez1, Hector Rene Vega-Carrillo2, Marco A. de Sousa Lacerda3, Karen A. Guzmán-García4 1 Laboratorio de Patrones neutrónicos. CIEMAT, Madrid Spain Universidad Autonoma de Zacatecas. Zacatecas, Zac. Mexico 3 Laboratório de Calibração de Dosímetros, CDTN/CNEN, Belo Horizonte, Brazil 4 Departamento de Ingenieria Energetica, ETSI Industriales, UPM, Madrid, Spain 2 * Email: [email protected] Abstract Neutron Standards Laboratory (LPN) is the Spanish national reference for calibration of neutron detectors. It counts with two calibration sources, 252Cf and 241Am-Be following the ISO8529-1 recommendations [1]. A detailed characterization of the neutron field for both sources has been performed in a previous work [2] making use of MCNPX simulations. Now, a study of the neutron spectra for both sources has been carried out with the CIEMAT-Bonner Spheres neutron spectrometer. This system has 3-to-12 inches-diameter polyethylene spheres with a 3He proportional counter as thermal neutron detector that is allocated at the spheres´ center. A set of 11 shadow cones have been used with both neutron sources in order to distinguish between direct and scattered contribution. Obtained spectra are compared with simulations and with neutron sources defined in the standard ISO85291, which is under revision at this moment [3]. [1] ISO, International Organization for Standardization. Reference Neutron Radiations. Characteristics and Methods of Production. ISO-Standard 8529, Part 1; (2001). [2] Guzman-Garcia, KA, et al., (2015). App Rad Isot 100: 84-89. [3] Bedogni, R. et al., (2014). Nucl Inst Meth Phys Res A 763: 547–552. Keywords: Neutron sources; 252Cf; 241Am-Be; Neutron spectrometry; Bonner Spheres. 50 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Evaluation of patient absorbed dose in a PET-CT test Fernanda Guerra Paiva1, Priscila do Carmo Santana2 and Arnaldo Prata Mourão1,3 1 Department of Nuclear Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627, CEP: 31270-90, Pampulha, Belo Horizonte, MG, Brazil 2 Medical School, Federal University of Minas Gerais, Av. Professor Alfredo Balena, 190, CEP: 30123970, Santa Efigênia, Belo Horizonte, MG, Brazil 3 Biomedical Engineering Center, Federal Center for Technological Education of Minas Gerais, Av. Amazonas, 5253 - Sala 113. CEP: 30421-169, Nova Suíça, Belo Horizonte, MG, Brazil Email: [email protected] Abstract Images of Positron Emission Tomography (PET) associated with Computed Tomography (CT) have important diagnostic applications, especially in oncology. This equipment allows overlapping of functional images obtained by using radionuclides and anatomical, generated by x-rays. The PET-CT technique, when compared to other diagnostic techniques, may generate higher doses in patients because two diagnostic modalities are used in a single examination. A whole body CT scan is performed and a subsequent capture of the signal generated by the photons emitted from the decay of a positron emitting radionuclide. This photon detection is made by the PET acquisition system[1]. The efficiency of this conversion is known as sensitivity, the number of counts per unit of time detected by the device, per unit of source activity and depends on the system geometrical characteristics and the detection mode, ie, varies in each equipment. In this study the absorbed doses generated by the CT scan and incorporated by the administration of the radionuclide were evaluated. The absorbed doses was evaluated in the following organs: brain, pituitary, crystalline, thyroid, cervical spine, breasts, lungs, heart, stomach, liver, pancreas, spleen, vesicle, kidneys, colon, sigmoid, small intestine, bladder and testicles. To evaluate the CT dose 32 radiochromic film strips were correctly positioned into the anthropomorphic male phantom, Alderson model. The protocols performed were whole-body scanning and a high-resolution lung scan. The calculation of the effective dose from the injected activity in patient was performed using the ICRP 106 Biokinetic model [2]. The phantom mass used is 73.5 kg, then the simulation considered an injected activity of 3.33 MBq x 73.5 kg. The highest absorbed doses were found in the thyroid and bladder, corresponding to approximately 78 mGy and 63 mGy respectively. The use of 18FDG contributes with 63% to the absorbed dose in the brain due to its biodistribution. As conclusion, it is observed that the dose in patients submitted to the 18F-FDG PET-CT examination is high, being of great value efforts for its reduction, such as the use of appropriate image acquisition techniques and promoting the application of the principle of optimization of practice. [1] Robilotta, C.C. (2006). Rev Pan Salud Publ, 20: 134–142. [2] ICRP- INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION. The 2007 Recommendations of the International Commission on Radiological Protection. Radiation Dose to Patients from Radiopharmaceuticals. ICRP Publication 106, 2008. Keywords: Computed Tomography; PET-CT test; Dosimetry. 51 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Estudio mediante métodos Monte Carlo de un sistema de detección de explosivos utilizando un generador D-D y detectores de NaI(Tl) Lenin E. Cevallos-Robalino1*, Karen A. Guzmán-García1, Eduardo Gallego1, Gonzalo García-Fernández1, Hector Rene Vega-Carrillo2 1 Departamento de Ingeniería Energética, ETSI Industriales, Universidad Politécnica de Madrid C. José Gutiérrez Abascal 2, 28006, Madrid, España 2 Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas C. Ciprés 10, Fracc. La Peñuela, 98060, Zacatecas, Zacatecas, México * Buzón-e: [email protected] Resumen La detección de material explosivo oculto es de suma importancia para la seguridad nacional. Mediante métodos Monte Carlo, con el código MCNP6, se han evaluado diversas configuraciones propuestas de un sistema de detección con un generador de DeuterioDeuterio, D-D, en conjunto con detectores de centello de NaI(Tl), para interceptar explosivos ocultos. Se analiza la respuesta del sistema ante diversas muestras de explosivos tales como el RDX y Nitrato de Amonio por ser los principales componentes de los explosivos casero-militar. El generador D-D produce neutrones rápidos de 2.5 MeV en un campo máximo de 1010 n/s (DD-110) el cual es rodeado con polietileno de alta densidad con el fin de termalizar los neutrones rápidos logrando que interaccionen con la muestra inspeccionada, dando lugar a la emisión de rayos gamma obteniendo un espectro característico de los elementos que la constituyen, pudiendo de esta manera determinar su composición química e identificar el tipo de sustancia. Se evalúa el blindaje necesario para estimar la dosis admisible de operación, con espesores de plomo y polietileno de alta densidad borado, con el fin de situarlo en algún punto del Laboratorio de Medidas neutrónicas de la Universidad politécnica de Madrid donde el blindaje sea óptimo. Los resultados muestran que su funcionalidad es prometedora en el campo de la seguridad nacional para inspección de explosivos. Palabras clave: MCNP6; RDX; Nitrato de amonio; D-D; Centellador de NaI(Tl). 52 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Radiochromic film calibration for dosimetry in Computed tomography tests Kamila Cristina Costa1, Káren Larissa Costa3, Alvaro Maurício Ladino Gómez 2, Arnaldo Prata Mourão1,2,* 1 Biomedical Engineering Center, Federal Center for Technological Education of Minas Gerais, Av. Amazonas, 5253 - Sala 113. CEP: 30421-169, Nova Suíça, Belo Horizonte, MG, Brazil 2 Department of Nuclear Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627, CEP: 31270-90, Pampulha, Belo Horizonte, MG, Brazil 3 Medicine Department, University of Itaúna Mg 431 Km 45 - Eldorado, Itaúna, MG, Brazil. * Email: [email protected] Abstract Radiochromic film applications in dosimetry have become increasingly significant for studies on radiotherapy and diagnostic tests. Due to sensitivity to exposure to ionizing radiation, radiochromic films are commonly used to obtain dose distribution maps. The objective of this study is to obtain the calibration curves of the radiographic film for exposure with X-ray beam in a computerized tomography (CT) scanner for realize measures of typical doses found in radiodiagnosis tests[1]. It was used Gafchromic XR-AQ2 film, which show little sensitivity to visible light and a response in the range of 0.1 to 20 cGy for X-ray beam in a tube voltage supply range ranging from 20 kV to 200 kV[2]. In the experiments, a head polymethylmethacrylate (PMMA) phantom, with a cylindrical shape with five openings was used. This phantom was placed in the CT scanner isocenter and radiochromic film strips were placed into two openings. The irradiations were performed in a Toshiba Asteion scanner that allows making acquisitions in helical mode. The central slice of the head phanto was irradiated to obtain the values of kerma in PMMA measured with a pencil ionization chamber. Thereafter, radiochromic film strips were placed into the central and one peripheral opening and 10 cm long scans of the central region of the phantom were carried out with feed voltage of 120 kV. The strips irradiated with differents X-ray tube currente were scanned and processed using the ImageJ software to obtain the intensity values resulting from the absorbed radiation by optical density analysis. The calibration curves were obtained for both region, central and peripheral corresponding to the values of kerma in PMMA measured with ionization chamber. With the curves in hand, CT experiments with applied beams can use radiochromic films as a dosimetry method and then seek the generation of images with lower dose deposition and higher diagnostic quality. [1] Morrison H, Menon G, Sloboda RS. (2014). Med. Phys., 41(7): 072101-1 – 0.72101-11. [2] Giaddui, T. et al. (2012). Med. Phys., 39(2): 842-850. Keywords: Dosimetry; Radiochromic film; Computed Tomography. 53 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Photoluminescence properties of PBAT/Amylum blends applied to radiation dosimetry Elisete Lopes da Cunha1,*, Giovana Ribeiro Ferreira2, Rodrigo Fernando Bianchi3, Luiz Oliveira de Faria4,* 1 Departmento de Eng. Nuclear, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil 2 Universidade Federal dos Vales do Jequitinhonha e Mucuri, Janaúba, MG, Brazil 3 Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil 4 Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, MG, Brazil * Email: [email protected] Abstract Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable aliphatic-aromatic copolyester. The radio induction of photoluminescence (PL) properties in PBAT was reported to appear after exposure to high doses of gamma radiation [1, 2]. After the previous high-energy irradiation, the material shows the highest photo-stimulated luminescence emission when excited with a light-emitting diode (LED) source at wavelengths ranging from 370 to 405 nm. The PL intensities at 490 nm obtained after excitation with a LED source of 405 nm are proportional to gamma doses ranging from 100 to 1000 kGy. In this work, we report the effects of mixing PBAT with Amylum in the PL output of PBAT. The [C6H10O5]n monomers also contains benzene rings which in turn is thought to be transformed into photoluminescent aromatic amines under gamma irradiation. The collected PL emission spectra of PBAT/Amylum revealed a PL output around three times higher than that of PBAT. This enhanced PL property makes PBAT/Amylum blends to be good candidates for application in bioimaging devices and radiation dosimetry. [1] Schimitberger, RT, et al., (2014) IEEE Trans. Nucl. Sci., 61: 1-10. [2] Schimitberger, RT, et al., (2013) Int. J. Microwave Wireless Tech., 1576: 7-9. Keywords: Bioimaging devices; Photoluminescent polymers; Poly(butylene adipate-coterephthalate) PBAT; Radiation dosimetry. 54 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Optimización del código PENELOPE en lenguaje F# para la simulación del espectro de rayos X en radiodiagnostico Christopher Irvin Ballon Peralta, Nelly Ysabel Quispe Valeriano, José Vega Ramirez Universidad Nacional de San Agustín de Arequipa CP 04000, Arequipa, Perú Buzón-e: [email protected] Resumen La simulación computacional es una herramienta poderosa, en nuestro caso utilizada para simular el transporte de radiación y partículas para obtener el espectro de rayos-x en el rango de radiodiagnóstico, esta simulación, permite un estudio y conocimiento antelado del proceso de transporte de los rayos-X en la interacción con la materia (paciente), usando el método Montecarlo. Con la obtención de los espectros de rayos-x podremos conocer la dosis que recibe el paciente cuando se somete a un estudio radiográfico o TAC, mejorando la calidad de la imagen obtenida. El objetivo del presente trabajo fue optimizar el código PENELOPE versión 2008 (Código Monte Carlo para la simulación del transporte de electrones y fotones en la materia) agregando código en lenguaje funcional F#, para el procesamiento en paralelo del proceso de simulación, para nuestro caso, la simulación del espectro de rayos-x de un equipo Siemens Seregraph, dónde estos resultados fueron validados con datos experimentales obtenidos en la medición del espectro de rayos-x mostrados en el reporte 78 del IPEM (Instituto de Física e Ingeniería aplicados a la medicina) obteniéndose una buena concordancia y reduciendo el tiempo de simulación a la mitad, al optimizar el algoritmo en si y la utilización de los recursos del sistema en ordenadores de varios núcleos algo no contemplado por el software programado inicialmente en FORTRAN 77. Además el software optimizado en cuestión también posee las mismas prestaciones de PENELOPE, como por ejemplo simulación de procesos a altas energías. Palabras clave: Espectro de rayos-X; PENELOPE; Lenguaje F#; Simulación. 55 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. NaI(Tl) detectors modeling in MCNPX and Gate/Geant4 codes Renato Raoni Werneck Affonso1, Ademir Xavier da Silva1, César Marques Salgado2 1 Universidade Federal do Rio de janeiro (UFRJ) Instituto de Engenharia Nuclear (IEN/CNEN) 2 Email: [email protected] Abstract NaI (Tl) detectors are widely used in gamma-ray densitometry, but their modeling in Monte Carlo codes, such as MCNP-X and Gate/Geant4, can need a lot of work and do not yield comparable results with an experimental arrangement due to possible non-simulated physical phenomena, such as light transport within the scintillator. Therefore, it is necessary a methodology that impacts positively in the results of the simulations and, at the same time, maintains the real dimensions of the detectors and other objects, so it will be possible to validate a modeling that matches to the experimental arrangement. Thus, the objective of this work is to present the studies made with the MCNP-X and Gate/Geant4 codes, in which the comparisons of their results were satisfactory, showing that both can be used for the same purposes. Keywords: Monte Carlo; Gamma densitometry; Artificial neural network; Volume fraction. 56 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Caracterización de tejidos equivalentes al cuerpo humano mediante el método Monte Carlo para rayos X José Vega Ramírez1*, Yemby Huamani Tapia1, Arnol Mullisaca1, Lisbeth Yauri Condori1 Escuela de Física, Universidad nacional San Agustín de Arequipa Arequipa,Perú * Email: [email protected] Resumen La necesidad de tener materiales equivalentes al cuerpo humano que tenga las características apropiadas para ser utilizado como tejido sustitutos en las prácticas clínicas de Radiodiagnóstico, radioterapia. En Arequipa-Perú se tiene dos centros de salud en aplicaciones en radioterapia uno con irradiador gamma Terathrom Co-60 y otro un LINAC de Elekta, la Escuela de Física de la Universidad Nacional de San Agustín de Arequipa área de física médica, se construyeron cuatro materiales equivalentes a base de resina epoxi, esferas fenolíticas, carbonato de calcio etc., como tejido óseo, tejido blando, tejido adiposo y tejido pulmonar comparados con el agua. Con el objetivo de estudiarlos y aplicarlos en futuras aplicaciones clínicas. En este trabajo describimos su caracterización física y dosimétrica para determinar su utilización como material equivalente o maniquí. Los materiales construidos, son discos de 1 cm de espesor y 30 cm de diámetro, los materiales son sólidos no maleables , no se degrada, presenta estabilidad en su consistencia por la temperatura y la irradiación, no es toxico en su utilización, determinando las densidades desde 0,32 g/cm3 para el tejido pulmón hasta 1,8 g/cm3 para el material hueso, fueron analizado por microscopia electrónica de barrido SEM, dando los porcentaje por peso de los elementos encontrados para determinar su número atómico efectivo el análisis físico para determinar sus coeficientes de absorción másico y de energía[1], que fueron estudiados para fotones de energía entre 1 keV a 20 MeV, la simulación de los materiales equivalentes y el estudio Físico y dosimétrico fueron encontrados de acuerdo el código PENELOPE 2008 Método Monte Carlo y validados por base de datos de NIST. Los resultados obtenidos de acuerdo a sus coeficientes de atenuación másico de cada material, muestran al tejido pulmonar, tejido óseo, tejido blando y tejido adiposo tienen diferencias con respecto del agua en un porcentaje de 1,2%, 42,2%, 3,7% y 12,7%. El análisis dosimétrico PDP se realizó con radiación gamma (Co-60), y rayos X de alta energía (6MV) [1] Vahabi SM, Bahreinipour M & Zafarghandi MS. (2017). Vacuum 136: 73-76. Palabras clave: Materiales equivalentes; Coeficiente de absorción; PDP; PENELOPE. 57 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Optically stimulated luminescence properties of Tm3+ doped KMgF3 fluoroperovskite Luis Camargo1, L. Pérez-Cruz2, E. Cruz- Zaragoza2, S.A. Martínez-Ovalle3, J. Marcazzó1,* 1 Instituto de Física Arroyo Seco (UNCPBA) and CIFICEN (UNCPBA – CICPBA – CONICET), Pinto 399, 7000, Tandil, Argentina 2 Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México A.P. 70543, 04510 México D.F., México 3 Grupo de Física Nuclear Aplicada y Simulación Universidad Pedagógica y Tecnológica de Colombia, Tunja, Colombia * Email: [email protected] Abstract In this work the optically stimulated luminescence (OSL) properties of undoped and Tm3+doped KMgF3 fluoroperovskite have been investigated for the first time. OSL efficiency for stimulation with different wavelengths has been analyzed for each compound and maximum OSL emission was found when blue light is employed for stimulation. The radioluminescence (RL) spectra have shown two emission peaks at 455 and 360 nm, which can be ascribed to the 1D2–3F4 and 1D2–3H6 transitions of the Tm3+ cations. It has been found that doping with Samarium at 0.5 mol % renders the most intense OSL emission. Furthermore, several dosimetric properties such as OSL response as a function of dose, reproducibility of the OSL signal after several cycles of irradiation-readout and the minimum detectable dose have been investigated. Finally, the OSL response of KMgF3:Tm3+ has been compared to that of commercial Al2O3:C and the possible application of this fluoroperovskite to OSL dosimetry has been evaluated. Keywords: Optically Stimulated Luminescence; Fluoroperovskite; Dosimetry. 58 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Angular characterization of the response of an YVO4:Eu3+ - based radioluminescence probe under LINAC irradiation Yohanna Fernandez1,*, Nahuel Martinez2, Julián Marcazzó2, Martín Santiago2, Pablo Molina2,* 1 2 Department of Physics, UNCPBA, Pinto 399, 7000 Tandil, Argentina. Instituto de Física Arroyo Seco (UNCPBA) and CIFICEN (UNCPBA – CICPBA – CONICET), Pinto 399, 7000, Tandil, Argentina. * Email: [email protected] Abstract Real-time dosimetry in radiotherapy with high spatial resolution is a constantly growing research field. Accurate radiotherapy techniques such as, gynaecological brachytherapy, intensity-modulated radiation therapy, intraoperative radiation therapy, stereotactic radiosurgery, among others, require dosimeters with the characteristics mentioned before. Even though different kinds of detection systems have been investigated to perform in-vivo dosimetry, most of them do not provide simultaneously spatial resolution, real-time dose assessment and intracavitary measurements. The so-called fiberoptic dosimetry (FOD) technique has shown to meet most of these requirements mostly needed in radiotherapy [1]. This technique is based on the use of a tiny piece of a scintillation crystal, which is attached at the end of an optical fiber [1]. The fiber collects the light emitted by the scintillator during irradiation (radioluminescence, RL) and a light detector placed at the other extreme of the optical fiber measures its intensity. FOD technique allows for in-vivo and real-time dose assessment, and due to the small size of the detector it not only permits accurate measurements in regions of high dose gradients but also intracavitary measurements [2]. Martinez et al. [3] observed angular dependency of the scintillating signal when cylindrical detectors are employed as usual in this technique. In the present work we report the angular response of an YVO4:Eu3+ based FOD probe. YVO4:Eu3+ powder was dispersed in UV curing adhesive to obtain a 2 mm diameter spherically shaped detector, which was glued at the end of an optical fiber. [1] Justus, B.L. et al., (2004). Appl Opt 43: 1663-1668. [2] Spasic, E., et al., (2011). Nuclear Instrumentation Measurement Methods and Their Applications (ANIMMA). Pp. 1-6. [3] Martinez, N. et al., (2017), Rad Meas., (in press). Keywords: Fiber Optic Dosimetry; Radioluminiscence; Real Time Dosimetry. 59 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. X-ray production in different anode geometries: Theoretical and Monte Carlo simulation approaches R. Figueroa1,2,*, F. Geser3,4, F. Malano1,3,4, M. Santibáñez1,2, M.Valente1,2,3,4 1 Departamento de Ciencias Físicas, Universidad de La Frontera, F. Salazar 01145, Temuco, Chile. 2 Centro de Física e Ingeniería en Medicina - CFIM, Universidad de La Frontera, Temuco, Chile. 3 Instituto de Física E. Gaviola – CONICET & Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Universidad Nacional de Córdoba, Av. M. Allende s/n, Argentina. 4 FaMAF, Universidad Nacional de Córdoba, Av. M. Allende s/n, Argentina. * Email: [email protected] Abstract X-rays are commonly used for a wide variety of purposes, from material characterization to medical applications. The traditional scheme for X-ray production is based on the well known X-ray tube, an evolution in technology started from the experiments performed by Crookes and finally by X-rays discovery by W. Röntgen in 1895. As known, X-ray tubes are mainly based on the impact of accelerated electron onto high atomic number anodes in order to produce photons by means of Bremsstrahlung and characteristic X-rays. However, spectral and angular distributions of produced photons may not be strictly improved, or even worst, not adequate for specific applications. Actually, one of the main properties of traditional X-ray tubes regards its geometrical divergence, which necessary produces fluence reduction along beam trajectory. This inherent characteristic represents a strong limitation when high concentrated fluence is required, as happens in convergent techniques [1] . This work presents investigations about the effects of the different anode properties in combination with electron beam incidence in order to assess convenient X-ray tube designs to produce X-rays with different purposes, mainly focused on applications requiring photon fluence concentration. Dedicated Monte Carlo subroutines (PENELOPE [2] and FLUKA [3]) were developed aimed at describing interaction processes and X-ray production according to different combination of electron beam incidence and anode physical/geometrical properties. The obtained results confirm that suitable designs are capable of improving photon fluence at certain regions according to specific requirements. [1] Figueroa, F. & Valente, M. (2015). Phys. Med. Biol. 60: 7191-206. [2] Salvat, F., Fernández-Varea, J., Sempau, J. (2008). PENELOPE Version 2008, NEA, France. [3] Battistoni, G. et al., (2007). AIP Conf. Proc. 896, 31-49. Keywords: X-ray production; Convergent photon beam; Monte Carlo simulation. 60 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Theory, simulation and experiments for precise deflection control of radiotherapy electron beam R. Figueroa1,2,*, L. Leiva2, R. Moncada1,2, L. Rojas2, M. Santibáñez1,2, M. Valente1,2,3, J. Velásquez2,4 , H. Young1,2 1 Centro de Física e Ingeniería en Medicina - CFIM, Universidad de La Frontera. Temuco, Chile. 2 Universidad de La Frontera, Temuco, Chile. 2 Departamento de Ciencias Físicas, Universidad de La Frontera, F. Salazar 01145, Temuco, Chile. 3 Instituto de Física E. Gaviola – CONICET & Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Universidad Nacional de Córdoba, Av. M. Allende s/n, Argentina. 4 ICOS Inmunomédica, Temuco, Chile. * Email: [email protected] Abstract Conventional radiotherapy is mainly applied by linear accelerators (linac). Although linacs provide dual (electron/photon) radiation beam modalities, both of them are intrinsically produced by an initial high energy (megavoltage) electron current [1]. Several modern radiotherapy treatment techniques nowadays worldwide available are based on suitable devices inserted or attached to conventional linacs [1,2]. In this framework, one of the main key issues regards the precise control of delivered beam, which is usually modified/modulated/redirected by means of dedicated devices. This work presents an integral description of electron beam deflection control as required for novel radiotherapy technique based on convergent photon beam production. Theoretical and Monte Carlo approaches were initially used for designing and optimizing device´s components. Then, dedicated instrumentation was developed for experimental verification of electron beam deflection due to the designed magnets. Both Monte Carlo simulations and experimental results support the reliability of electrodynamics models used to predict megavoltage electron beam control [3]. [1] Kahn, F. THE PHYSIS OF THE RADIATION THERAPY, Williams & Wilkins (2009). [2] Mayles, P., Nahum, A., Rosenwald, J.C. HANDBOOK OF RADIOTHERAPY PHYSICS: THEORY AND PRACTICE, CRC Press (2007). [3] Figueroa, F. &Valente, M. (2015). Phys. Med. Biol. 60: 7191-206. Keywords: Electron beam deflection; Convergent photon beam; Monte Carlo simulation. 61 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Assessment of LabSOCS as a tool for the calculation of self- attenuation coefficients in gamma spectrometry José Lopes1,*, Marcos Paulo de Medeiros1,3, Ricardo Garcêz1, Rogério Filgueiras1, Jardel Thalhofer1, Wilson Freitas Rebello3,4, Ademir Xavier da Silva1,2 1 Universidade Federal do Rio de Janeiro, Programa de Engenharia Nuclear. Av. Horácio Macedo, 2030 - CT, Fundão, 21945-970 - Rio de Janeiro, RJ - Brasil 2 Universidade Federal do Rio de Janeiro, Escola Politécnica Av. Athos da Silveira Ramos, 149 – CT, Fundão, 21941-909 - Rio de Janeiro, RJ - Brasil 3 Instituto Militar de Engenharia – IME, Seção de Engenharia Nuclear. Praça General Tibúrcio, 80, Urca, 22290-270 - Rio de Janeiro, RJ – Brasil 4 Universidade do Estado do Rio de Janeiro, Departamento de Estruturas e Fundações. R. São Francisco Xavier, 524, Maracanã, 20550-900 - Rio de Janeiro – RJ * Email: [email protected] Abstract In spectrometry, the self-attenuation coefficients are fundamental to correct the efficiency of the detection of samples whose density is different from the radioactive standard. To facilitate the procedure of coefficient calculation, mathematical simulations have been widespread as a tool. In this paper, LabSOCS was used to calculate the self-attenuation coefficients for some geometries and the values found were compared to those obtained with MCNPX and experimental values. The percentage deviations found for the selfattenuation coefficient calculated by LabSOCS were below 1.6%, when compared to experimental values. In the extrapolation zone of the fitting curve of the experimental model, the deviations were below 1.9%. The results obtained show that the deviations increase proportionally to the amplitude between the density values of the radioactive standard and the sample. High percentage deviations were also obtained in simulations whose samples had high densities, complex geometries and low energy levels. However, the results indicate that LabSOCS is a tool which may be used in the calculation of selfattenuation coefficients. Keywords: Self-attenuation; Gamma Spectrometry; MCNPX; LabSOCS. 62 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Influencia de los rayos X de frenado en la calidad de las imágenes SPECT con Itrito-90 utilizando simulación Monte Carlo Carlos O. Pastrana Orejuela1,*, Ademir X. da Silva2, Mirta B. Torres Bedeguez3, Programa da Engenharia Nuclear1,2,3, Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa em Engenharia1,2,3, Universidade Federal Do Rio de Janeiro1,2,3. * Buzón-e: [email protected] Resumen El itrio-90 es uno de los radiofármacos más utilizados en la Medicina Nuclear Terapéutica. Las características energéticas de este emisor beta puro constituyen una dificultad para la planificación de dosis usando imágenes SPECT. El objetivo de este trabajo es realizar un estudio de la influencia de los rayos X de frenado emitidos por el itrio-90 en la adquisición de imágenes SPECT, considerando los materiales que constituyen el cuerpo humano. Mediante el uso del código Monte Carlo MCNPX 2.5, se realizaron varias simulaciones para evaluar aspectos que podrían afectar la calidad de la imagen SPECT, como el tipo de colimador, la distancia fuente-colimador, la geometría y la composición de los materiales. La simulación con MCNPX 2.5 fue experimentalmente validada en comparación con la distribución espectral de los rayos X de frenado del itrio-90 en el cristal detector NaI(Tl) con el espectro ofrecido por el propio sistema SPECT de la marca General Electric, instalado en el Departamento de Medicina Nuclear del Hospital Universitario Clementino Fraga Filho. Para ello, se simulo la adquisición de la imagen estática generada por una fuente de itrio-90, uniformemente distribuida en el volumen interno de agua y contenida en un frasco cilíndrico de 18,4 cm de altura y 2,2 cm de radio, a una distancia fuente colimador (LEHR) de 10 cm. Los resultados obtenidos en este trabajo muestran que es posible realizar una planificación de dosis en paciente específico utilizando imagen diagnóstica SPECT con itrio-90. Palabras clave: Frenamento; Monte Carlo; SPECT. 63 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Simulación del espectro (Co - 60), Theratron Equinox, usando el código PENELOPE v. 2008 Nelly Ysabel Quispe Valeriano, Cristina D. Santos Flores, Christopher I. Ballón Peralta, José Luis J. Vega Ramirez Universidad Nacional de San Agustín, 04.000-Perú Hospital III Goyeneche , 04.000-Perú Buzón-e: [email protected] Resumen Usando el código PENELOPE (PENetration and Energy LOss of Positrons and Electrons) V.2008 se obtuvo el espectro de la unidad de cobalto Theratron Equinox, utilizado actualmente en el hospital Goyeneche de Arequipa, en el servicio de radioterapia. Se utilizó el programa penmain para la obtención del espectro que junto al paquete PENGEOM incluidos en el código PENELOPE, nos permitió la construcción de estructuras complejas como en este caso del cabezal de unidad de Cobalto que comprende esencialmente la fuente de cobalto y sus colimadores. Se obtuvo también las curvas de porcentaje de dosis a profundidad (PDD siglas en inglés) en diferentes tamaños de campos irradiados de 5x5, 10x10 y 15x15 cm2 para el espectro de cobalto obtenido, en los cuales se observa que hay mayor dispersión para campos mayores y se necesitó mayor tiempo de simulación, hallándose concordancia de los resultados de la simulación, al comparar los datos obtenidos experimentalmente de la dosis con la cámara de ionización en una cuba de agua. El espectro obtenido fue validado con los datos de la cámara de ionización en la determinación de las curvas de PDD, puede usarse como una referencia para optimizar el sistema de planificación de radioterapia en la simulación con materiales equivalentes al cuerpo (phantom). Palabras clave: Radioterapia; Co-60; Unidad de cobalto. 64 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Determination of the dose enhancement due to Gadolinium using EBT2 and EBT3 gafchromic films irradiated with 192 Ir, 241Am, and low-energy X-ray sources M. Santibáñez1,2*, Y. Guillen1, M. Valente1,2,3, R. Figueroa1,2. 1 Departamento de Ciencias Físicas, Universidad de La Frontera, Temuco, Chile. Centro de Física e Ingeniería en Medicina - CFIM, Universidad de La Frontera, Temuco, Chile. 3 Instituto de Física E. Gaviola – CONICET & Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Universidad Nacional de Córdoba, Argentina. 2 * Email: [email protected] Abstract This work reports on the relative local dose enhancement produced in phantoms containing target volumes doped Gd irradiating with 192Ir (Gamma MedplusiX) barchytherapy, 241Am isotope and suitably configured X-ray beams [1-3]. EBTs and EBT3 Gafchromic films were immersed into 1.7ml target volumes to mimic tumor filling with 100% ultra pure water (blank sample) and ultra pure water infused with 71.86mg/l of Gd solution (Omniscam®) normally used for magnetic resonance imaging. Tumor phantoms were irradiated using 10Ci 192I source during 1 minute, an annular 0.1Ci 241Am source during 24 hours, and different configurations of X-ray tube during 1 minute and testing also the effects of varying accelerating voltage: 60, 75 And 90 kV and incorporating 2.9 mm Cu filtering for 1 min [3]. Thus, dose enhancement due to excitation of Gd K-edge (50.2 keV) was evaluated in terms of optical density variations. Statistical uncertainties were suitably reduced performing 10 equivalent measurements for each irradiation configuration. Tumor phantoms doped with different Gd concentrations (1.0-40 mg/l) were used to obtain the corresponding calibration curve of local dose enhancement within the tolerance range for in-vivo applications [1]. The obtained results confirmed increments in relative dose enhancement according to Gd concentrations. As expected, higher increase were observed when irradiating with energy close o the Gd K-edge suggesting the potentiality of 241Am as well as electronic brachyherapy to attain local dose enhancement by Gd-infusion. [1] D.G. Zhang, V. Feygelman, E.G. Moros, K. Latifi, G.G. Zhang. PLoS ONE 9 (2014) e109389. [2] Brachitherapy devices and methods employing americium-241, Patent US4510924. 3 M. antib ez, M. V squez, .G. Figueroa, M. Valente, adμ Phys. Chem. 122 (2016) 28-34. Keywords: Dose enhancement, Gd-infused tumor irradiation, Brachitherapy. 65 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Simulation of lung cancer treatment with equivalent dose calculation and analysis of the dose distribution profile Jardel Lemos Thalhofer1,*, José Marques Lopes1, Ademir Xavier da Silva1, Wilson Freitas Rebello da Silva Junior2, Juraci Passos dos Reis Junior1, Samanda Cristine Arruda Correa3, Edmilson Monteiro de Souza4, Delano Valdivino Santos Batista5 1 Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil Universidade Estadual do Rio de Janeiro, Rio de Janeiro, Brazil 3 Comissão Nacional de Energia Nuclear, Rio de Janeiro, Brazil 4 Centro Universitário Estadual da Zona Oeste, Rio de Janeiro, Brazil 5 Instituto Nacional do Câncer, Rio de Janeiro, Brazil 2 * Email: [email protected] Abstract Actually, lung cancer is one of the most lethal types [1], due to the disease in the majority of the cases asymptomatic in the early stages, being the detection of the pathology in advanced stage, with tumor considerable volume [2]. Dosimetry analysis of healthy organs under real conditions is not feasible. Therefore, computational simulations are used to auxiliary in dose verification in organs of patients submitted to radiotherapy. The goal of this study is to calculate the equivalent dose, due to photons, in surrounding in healthy organs of a patient submitted to radiotherapy for lung cancer, through computational modeling. The simulation was performed using the MCNPX code [3], Rex and Regina phantom (ICRP 110) [4], radiotherapy room, Siemens Oncor Expression accelerator operating at 6MV and treatment protocol adopted at the INCA (National Cancer Institute – Brazil). The results obtained, considering the dose due to photons for both phantom indicate that organs located inside the thoracic cavity received higher dose, being the bronchi, heart and esophagus more affected, due to the anatomical positioning. Clinical data describe the development of bronchiolitis, esophagitis, cardiomyopathies with decreased cardiopulmonary function as one of the major effects of lung cancer treatment. In the Regina phantom, the second largest dose was in the region of the breasts with 615,73 mSv / Gy, while in the Rex 514,06 mSv / Gy, event related to the difference of anatomical structure of the organ. Through the tmesh command, a qualitative analysis was performed between the dose deposition profile of the planning system and the simulated treatment, with a similar profile of the dose distribution being verified along the patient's body. [1] INTERNATIONAL AGENCY FOR RESEARCH ON CANCER, 2012, "GLOBOCAN 2012: Estimated Cancer Incidence, Mortality and Prevalence Worldwide in 2012", IARC, Lyon, France. [2] Estimate/2016 – Cancer Incidence in Brazil / Instituto Nacional de Câncer José Alencar Gomes da Silva – MINISTÉRIO DA SAÚDE, 122 p, Rio de Janeiro: INCA, 2015. 3 MCNPXTM U E ’ MANUAL. VE ION 2.5.0., Los Alamos National Laboratory report LA-CP-05-0369. April. 2005. 4 INTE NATIONAL COMMI ION ON ADIOLOGICAL P OTECTION, “ ealistic eference Phantomsμ An Icrp/Icru Joint Effort”, IC P Publication 110, 2008. Keywords: Lung cancer; Dose, MNCPX, Dosimetry. 66 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Síntesis y caracterización de fluoruro de litio activado con plata Emma Kareline Encarnación Encarnación*, Zacarías Guerrero, Julio Reyes Universidad Autónoma de Santo Domingo República Dominicana *Buzón-e: [email protected] Resumen En el presente trabajo se muestran parte de los resultados obtenidos en el desarrollo de la investigación que se ha estado realizando desde el 2015 titulada “ íntesis y Caracterización de Nuevos Materiales Termoluminiscentes para la Dosimetría de Radiaciones y sus Aplicaciones en alud”. En el desarrollo de la misma se ha realizado la síntesis de cristales de fluoruro de litio (LiF) puro y activados con diferentes concentraciones de plata (LiF:Ag); también se presentan muestras sintetizadas utilizando diferentes temperaturas, así como variando la concentración del solvente (agua-etanol). Los materiales sintetizados se caracterizaron a través de diferentes técnicas: microscopía electrónica de barrido (SEM por sus siglas en inglés), difracción de rayos X (XRD por sus siglas en inglés). Específicamente se presentan los resultados del cálculo del tamaño de los cristales de LiF utilizando la ecuación de Scherrer [1,2]. Dentro de los resultados se resalta una dependencia del tamaño de los cristales por medio de los siguientes factores: la cantidad de activador en la muestra, la temperatura a la cual se sintetizó la muestra, así como la cantidad de solvente en la síntesis. Las muestras presentan una fase cristalina cúbica simple. [1] V. Uvarov, I. Popov, Mater. Charact. 58 (2007) 883. [2] A.W. Burton, K. Ong, T. Rea, I.Y. Chan, Microporous Mesoporous Mater. 117 (2009) 75. Palabras clave: Fluoruro de Litio; Nanocristales; Temperatura de Síntesis. 67 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Study of carbon-doped micro and nanosized alumina for radiation dosimetry applications Críssia C. P. Fontainha1*, Neriene Alves2, Wilmar Barbosa Ferraz3, Luiz O. Faria3 1 Departamento de Anatomia e Imagem, Universidade Federal de Minas Gerais Belo Horizonte, MG, Brasil 2 Departamento de Engenharia Nuclear, Universidade Federal de Minas Gerais Belo Horizonte, MG, Brasil 3 Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN) Belo Horizonte, MG, Brasil * Email: [email protected] Abstract New materials have been widely investigated for ionizing radiation dosimetry for medical procedures[1,2]. Carbon-doped doped alumina (Al2O3:C) have been proposed as thermoluminescent and photoluminescent dosimeters [3,4]. In the present study nano and micro-sized alumina doped with different percentages of carbon, sintered under different atmosphere conditions, at temperatures ranging from 1300 °C to 1750 °C, were sintered and their dosimetric characteristics for gamma fields were investigated. Among the investigated sample preparation methods, the micro-sized alumina doped with 0.01% of carbon and sintered at 1700°C under reducing atmosphere has presented the best TL output, comparable to the best TL sensitivities ever reported to alumina and better efficiency than the nano-sized alumina synthesized in this study. The influence of humidity in the TL signal has been evaluated to be -4,0%. The micro-sized alumina obtained by the methodology used in this work is a suitable candidate for application in X and Gamma radiation dosimetry. [1] Weinstein, I. A. et al. (2008). Radiation Measurements. 43: 259-262. [2] SQUAIR, P. L. et al. (2005). Radio 2005. Rio de Janeiro, Brazil. [3] Akselrod, M. S. et al. (2007). Radiation Measurements. 41:S78–S99. [4] Marckmann, C. J. et al. (2006). Radiation Protection Dosimetry. 120: 28-32. Keywords: Carbon-doped doped alumina (Al2O3:C); Thermoluminescent dosimeters (TLD); Photoluminescent dosimeters (OSL). 68 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Electron paramagnetic resonance studies of a new luminescent material based on CaB6O10: Pb Leonardo V. S. França1,*, Luiz C. Oliveira1 & Oswaldo Baffa1 1 Universidade de São Paulo, FFCLRP-Departamento de Física, Ribeirão Preto-SP, Brasil. * Email: [email protected] Abstract A new photostimulable phosphor based on Pb-doped CaB6O10 was recently synthesized and its luminescence properties studied [1]. This material is very promising exhibiting high sensitivity to ionizing radiation, comparable or surpassing commercially available luminescence materials such LiF:Mg,Ti and Al2O3:C, with a dominant TL peak at ~200°C and an OSL signal that can be ~99% read within ~20 s under current experimental conditions. The Radioluminescence, Thermoluminescence and Optically Stimulated Luminescence signals are dominated by an emission band at ∼320 nm, probably associated with 3P1  1S0 transition of Pb2+. However, the involvement of the Pb dopant in the trapping process is not completely clear and Electron Paramagnetic Resonance (EPR) spectroscopy is being used to study the valence states of the Pb ion before and after irradiation. EPR measurements were carried out using a Jeol FX200 X-band spectrometer at liquid nitrogen temperature. Two concentrations of lead dopant in the CaB6O10 matrix were investigated. The material was irradiated with a dose of 500Gy using a 150kV X-ray tube at ambient temperature. The EPR spectrum shows the appearance of a symmetrical central line at g~2.0 and a line at high field at g ~1.2 with orthorhombic symmetry. This spectrum is similar to what was observed in the study of PbWO4 [2]. This study is under way with more experiments to correlate these findings with the luminescence properties. Acknowledgements: Partial financial support from the Brazilian Agencies: CAPES, CNPq and FAPESP. To C. A. Brunello for technical support. [1] Oliveira, LC & Baffa, O. (2017). J Lumin., 181: 171-178. [2] Laguta, VV et al., (2001). Phys Rev B, 64: 165102 Keywords: Electron paramagnetic resonance; Optically stimulated luminescence; Borate; Thermoluminescence; Dosimetry. 69 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Design of a technological tool for the solution of inverse problems using neural networks of reverse propagation with application to neutron spectrometry Víctor Hugo Castañeda-Miranda1*, Ma del Rosario Martínez-Blanco1, Luis Octavio SolísSánchez1, Rodrigo Castañeda-Miranda1, Hector Rene Vega-Carrillo2, Roberto Méndez3, Eduardo Gallego4, Marco Aurelio de Sousa Lacerda5, José Manuel Ortiz-Rodríguez1 1 Laboratorio de Innovación y Desarrollo Tecnológico en Inteligencia Artificial (LIDTIA) Unidad Académica de Ingeniería Eléctrica de la Universidad Autónoma de Zacatecas. Av. Ramón López Velarde, 801, Col. Centro, C.P. 98000, Zacatecas, Zacatecas, México. 2 Unidad Académica de Estudios Nucleares (UAEN), Universidad Autónoma de Zacatecas. C. Ciprés, 10, Col. Centro, C.P. 98000, Zacatecas, Zacatecas, México 3 Laboratorio de Patrones Neutrónicos del Departamento de Metrología de Radiaciones Ionizantes del Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) Avda. Complutense, 22, 28040, Madrid, España 4 Universidad Politécnica de Madrid (DIN-UPM) C. José Gutiérrez Abascal, 2, 28006, Madrid España 5 Centro de Investigación de Tecnología Nuclear de la Comisión Nacional de Energía Nuclear Av. Presidente Antonio Carlos, 6627, Pampulha, CEP: 31270-901, Belo Horizonte, MG, Brazil *Email: [email protected] Abstract Neural networks of reverse propagation have proved to be an effective tool for the solution of inverse problems, which are present in the dosimetry and neutron spectrometry. The problem of neural networks of reverse propagation is that it is not reported in the literature an optimal network architecture for each data set. This article presents a software tool capable of finding the optimal design values, which are the number of neurons in the first and second layers, the moment and the learning rate. The tool finds these values within a finite universe of possibilities, allows to configure the universe of search between the network design variables and randomly generates the training and testing percentages, you can select preloaded matrices experimentally generated in different laboratories, And filter the Bonner spheres that were used in the laboratories, so you can select the training type of the network, with this set of data find optimal network architecture values. The set of selected data is implemented in an orthogonal arrangement of Taguchi L9 L4, where there are 34 network performances corresponding to each network architecture, its average and its signal-to-noise ratio are calculated, then generates a local search among the best performances, and thus finds the optimum values of the network architecture for the desired data set. This article reports an example of the application of this tool in a set of data collected experimentally. Keywords: Artificial neural networks; Reverse Propagation; Optimal Network Architecture; Inverse Problems; Taguchi; Orthogonal Arrangement; Graphic Interface. 70 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Automated optimization of neural networks of reverse propagation using statistical techniques with application to neutron spectrometry Víctor Hugo Castañeda-Miranda1*, Ma del Rosario Martínez-Blanco1, Luis Octavio Solís-Sánchez1, Rodrigo Castañeda-Miranda1, Hector Rene Vega-Carrillo2, Roberto Méndez3, Eduardo Gallego4, Marco Aurelio de Sousa Lacerda5, José Manuel Ortiz-Rodríguez1 1 Laboratorio de Innovación y Desarrollo Tecnológico en Inteligencia Artificial (LIDTIA) Unidad Académica de Ingeniería Eléctrica de la Universidad Autónoma de Zacatecas. Av. Ramón López Velarde, 801, Col. Centro, C.P. 98000, Zacatecas, Zacatecas, México. 2 Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas. C. Ciprés, 10, Col. Centro, C.P. 98060, Zacatecas, Zacatecas, México 3 Laboratorio de Patrones Neutrónicos del Departamento de Metrología de Radiaciones Ionizantes del Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) Avda. Complutense, 22, 28040, Madrid, España 4 Universidad Politécnica de Madrid C. José Gutiérrez Abascal, 2, 28006, Madrid España 5 Centro de Investigación de Tecnología Nuclear de la Comisión Nacional de Energía Nuclear Av. Presidente Antonio Carlos, 6627, Pampulha, CEP: 31270-901, Belo Horizonte, MG, Brazil *Email: [email protected] Abstract The process that goes from loading experimentally generated data, randomly separating them to form training and test percentages, loading count rates, selecting the type of instrument, loading design variables (number of neurons in the first layer, Number of neurons in the second layer, moment and learning rate), filter the Bonner spheres, select the type of network training and simulate the network where it is required to apply least squares, generate correlation, calculate Chi square, calculate the performance and Perform a statistical adjustment, all this to find the performance of a single network, and then repeat this process 34 times based on the orthogonal arrangement of Taguchi, to generate a universe of different network architectures with their respective performances, and based on all The results discern which is the best, without a doubt, is a complex problem. Generating the aforementioned information requires considerable time and if human interaction occurs at any of its stages, it increases the probability of error. Therefore, this article reports a simple graphical interface for any user without requiring advanced programming skills, since it is intuitive and only allows to interact with the variables with which they want to do their experiment, this graphically and can not interact With the systematization of the process. Previously to generate this process, it required 3 different softwares and it was necessary to transfer the data from one software to another in a manual way which produced errors difficult to locate, this tool makes the processing of the different softwares in one, and dont exist The human interaction in the process. The graphing tool requires selection of the data set so that it is made intuitively and automatically generates the optimal network architecture of a neural network of reverse propagation. Keywords: Artificial neural networks; Reverse Propagation; Optimal Network Architecture; Automation; Taguchi; Orthogonal Arrangement; Graphic Interface. 71 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Thermoluminescence properties of MgO:Eu,Li obtained by glycine-based solution combustion synthesis M. A. Gortárez-Jiménez1,*, V. R. Orante-Barrón1, C. Cruz-Vázquez1, R. Bernal2 1 Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, Apartado Postal 130, Hermosillo, Sonora 83000 México. 2 Departamento de Investigación en Física, Universidad de Sonora, Apartado Postal 5088, Hermosillo, Sonora 83190 México. * Email: [email protected] Abstract There are only a few reports on luminescence dosimetry for undoped and doped MgO due to the lack of reproducibility for the luminescent signal in thermoluminescence (TL), regardless the synthesis method (i.e. solid state reactions, crystal growth, hydrothermal synthesis, co-precipitation synthesis, and sol-gel) [1]. Moreover, it is reported that introduction of alkaline metal ions into lanthanide-doped MgO enhances the photoluminescence (PL) signal significantly due to compensation charge effects with lanthanide ions [2-3]. Motivated by these previous results regarding stimulated luminescence on MgO, in this work, TL properties of MgO:Eu, Li synthesized by solution combustion synthesis (SCS), using glycine as fuel, are presented. The combustion was achieved at 500 oC, meanwhile, a flame and fumes emissions were observed. Powder samples obtained were annealed at 900 oC for 2 h in air. Characteristic TL glow curve of annealed MgO:Eu,Li powder samples, after being exposed to beta radiation, consists of a single defined peak located at ~ 400 °C. No shift is observed for this peak as the dose increases, suggesting that first-order kinetics processes predominate. [1] S. W. S. McKeever, M. Moscovitch and P. D. Townsend, Themoluminescence Dosimetry Materials: Properties and Uses (Kent: NTP) (1995).. [2] F. Gu, Ch. Li, H. B. Jiang, Journal of Crystal Growth 289 (2006) 400–404. [3] F. Gu, Ch. Li, H. Cao, W. Chao, Y. Hu, J. Chen, A. Chen, Journal of Alloys and Compounds 453 (2008) 361–365. Keywords: Thermoluminescence; Solution combustión synthesis. 72 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Quality image and incident air kerma evaluation in X-ray chest exams Paulo Márcio Campos de Oliveira1,*, Priscila do Carmo Santana1, Marco Aurélio de Sousa Lacerda2, Teógenes Augusto da Silva2 1 Department of Anatomy and Image, Federal University of Minas Gerais Belo Horizonte, Brazil 2 Nuclear Technology Development Center Belo Horizonte, Brazil * Email: [email protected] Abstract The procedures optimization for obtaining diagnostic quality images is an important factor to the patients radiation levels submitted to diagnostic radiology examinations was the lowest as reasonably practicable[1,2]. Two methodologies for image quality parameters evaluation were applied in the routine of three diagnostic radiology clinics (A, B and C), two with digital image processing and one with chemical processing in Belo Horizonte, Brazil. The incident air kerma was evaluated for the radiographic techniques used in the clinic routine chest exames, approved in accordance with European Image Quality Criteria[3,4]. It was possible to determine that the Fluke Biomedical X-ray Phantom test objects coupled to the Leeds Test Objects (TOR CDR) obtained better results than Gammex's Radiographic Survey Phantom (RSV), because the low and high contrast structures present in the RSV were not visualized in lower energies. The three clinics presented very similar results in all image quality parameters in the evaluation with the TOR CDR test object. However, clinic C presented an low contrast structures result 28.1% lower than clinical B, although the average Ka,i to obtain their images was 33.4% superior. The clinic A results present the best relation between image quality and radiation dose in patients. It was verified the optimization doses possibility in diagnostic radiology services with digital processing system, without significant reduction in image quality. Patients submitted to the highest radiation levels belonged to the clinic that presented the worst results in the image quality parameters evaluated. [1] Pina, D.R. (2009). Appl. Radiat. Isot. 67: 61-69. [2] ICRP. Radiological protection in medicine, ICRP 105. Ann. ICRP 37 (6), (2007). [3] Comission European Communities. (1996). European guidelines on quality criteria for diagnostic radiographic images. EUR 16260. [4] Comission European Communities. (1996). European guidelines on quality criteria for diagnostic radiographic images in paediatrics. EUR 16261. Keywords: Quality Image; Radiology Diagnostic; Dosimetry. 73 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Determination of Ra-226, Ra-228 and K-40 specific activities in samples of mineral fertilizer used in the Brazilian city of Rio de Janeiro Ricardo Washington Dutra Garcêz1,*, José Marques Lopes1, Jardel Lemos Thalhofer1, Marco Antônio Frota Lima2, Ademir Xavier da Silva1 1 Department of Nuclear Engineering, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil 2 Federal University Fluminense Niterói, RJ, Brazil * Email: [email protected] Abstract The use of fertilizers is a common practice, and several samples have radionuclides in their composition. Radiometric analyses these compounds are important because of its wide use, mainly to increase production by plants. Several samples of nitrogen, potassium, phosphate and mineral (NPK) compound fertilizer were acquired in the retail market of the city of Rio de Janeiro, and analyzed using gamma spectroscopy technique, with a high-purity germanium semiconductor detector (HPGe), and LabSOCS software for the calculation of the efficiency curve. The mean value of 40K specific activities found in the potassium fertilizer samples was 12,956 Bq·kg−1. In the samples of phosphate fertilizers, mean values of 506 Bq·kg−1and 499 Bq·kg−1 were found for 228Ra and 226Ra, respectively. And for NPK, the mean value of the specific activity found for 40K was 3,348 Bq·kg−1, and for 228Ra and 226 Ra the mean values found were 166.2 Bq·kg−1 and 114.8 Bq·kg−1, respectively. The values are consistent with those found in the literature, with the exception of the values for 228 Ra, probably due to the raw materials of the samples, and the absorbed dose associated with the 226Ra and 228Ra requires more detailed studies about the risks human health. Keywords: Fertilizers; Gamma-rays; HPGe. 74 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Calculation of dose profiles in cylindrical phantoms of water equivalent materials Alejandro L. Gonzales1,*, Lorena P. Robayo1, Paulo R. Costa1 1 Department of Nuclear Physics, Physics Institute, University of São Paulo, SP, Brazil * Email: [email protected] Abstract The adoption of Computed Tomography Dose Index (CTDI) measured in cylindrical simulators of materials equivalent to human tissue has become the standard procedure for dosimetric evaluation of CT equipment. Due to its original formulation, the CTDI can be calculated from the central and peripheral dose profiles generated in the exposure of a cylindrical phantom to the radiation beam. The present work aims to use the Monte Carlo method to calculate the dose profiles in cylindrical phantoms in order to obtain the corresponding CTDI. Materials equivalent to water generated in the Dosimetry and Medical Physics Group (GDFM) of the Institute of Physics of the University of São Paulo were used as material of cylindrical simulators [1]. Three water equivalent materials: H2O_1 (Propylene + Chloroethylene + Sodium hydroxide), H2O_2 (Propylene + Phosphorous acid + Sodium hydroxide) e H2O_3 (Polyethylene + Sodium hydroxide + Calcium Fluoride) were used to construct the cylindrical phantoms with 32 and 16 cm of diameter aiming to represent body and head phantoms, respectively. The PENELOPE/penEasy package in its 2014 version was used to simulate the radiation transport in the phantom and to determine the central and peripheral dose profiles. X-ray source models generated from spectra corresponding to the voltages of 80, 100, 120 and 140 kV, based on phase space files and incorporating the body and head bowtie filters, were used to obtain the dose profiles. The X-ray source model incorporates the anode effect, the angulation of the anode and the influence of the X-ray spectrum in the calculation of the dose profile. The central and peripheral dose profiles calculated on water equivalent materials will be used to calculate CTDI. CTDI results and dose profiles will be compared with literature data for reference materials. The results of this work will be used as reference to guarantee the usefulness of the materials developed in the GDFM in the manufacture of simulators for quality control of CT. [1] Mariano L., and Costa P. Development of a methodology for formulating radiologically equivalent materials to human tissues. Ph.D. Dissertation, Physics Intitute, University of São Paulo, 2017. Keywords: Dose profile; Water equivalent material; Monte Carlo simulation. 75 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Cuantificación de los niveles de Uranio en agua subterránea en el municipio de San Diego de la Unión, México Héctor Hernández-Mendoza1*, María Judith Ríos-Lugo2, Elizabeth Teresita Romero-Guzmán3, Dario Gaytán-Hernández2 1 Universidad del Centro de México San Luis Potosí, SLP. Capitán Caldera, 75, Colonia Tequixquiapan, 78250 San Luis, SLP. 2 Unidad de Posgrado, Facultad de Enfermería y Nutrición, Universidad Autónoma de San Luis Potosí, Avenida Niño Artillero 130, CP 78210, San Luis Potosí, S.L.P., México. 3 Departamento de Química, Gerencia de Ciencias Básicas-Tecnología Nuclear. Instituto Nacional de Investigaciones Nucleares. Carretera México-Toluca S/N km 36.5. C.P. 52750. A.P. 18-1027. La Marquesa Ocoyoacác México. *Buzón-e: [email protected] Resumen En este trabajo tuvo como objetivo la cuantificación de los niveles de uranio (U) en agua subterránea procedente de 23 pozos del municipio de San Diego de la Unión, México. Los pozos muestreados fueron clasificados como no regularizados y regularizados según registros de Comisión Nacional del Agua (CONAGUA) y clasificadas por zonas (A, B, C, D y E). Las muestras fueron recolectadas por triplicado en botellas de 1 L, posteriormente fueron acidificadas con HNO3 ultra puro al 2% v/v y conservadas a 4 ºC hasta su análisis por Espectrometría de Masas con Sector Magnético con Fuente de Plasma Acoplado Inductivamente (ICP-SFMS). El método de preparación fue la digestión ácida en abierto y reconcentración de la muestra. Además, 1 µg L-1 de indio (In) fue usando como trazador para conocer el rendimiento del método. Finalmente, las muestras fueron diluidas en 10 mL e introducidas al ICP-SFMS para medir en baja resolución los isótopos de U (234U, 235U y 238 U). Los resultados promedios obtenidos de U total fueron; A= 3.65±1.89 µg L-1, B= 6.37±1.46 µg L-1, C= 3.20±2.27 µg L-1, D= 3.87±1.31 µg L-1 y E= 4.44±1.17 µg L-1. Acorde con NORMA Oficial Mexicana NOM-014-CONAGUA-2003, lo niveles de U encontrados en las aguas subterránea de San Diego de la Unión no superan los límites permisibles de 30 µg/L. Palabras clave: Uranio; Agua subterránea; ICP-SFMS. 76 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Exploratory survey of initial image quality in new digital mammography units prior to use in patients in Mexico Enrique Gaona1, Enrique Gaona Castañeda2, Teodoro Rivera3, Nelly Molina1, Jesús Gabriel Franco1 1 Universidad Autónoma Metropolitana-Xochimilco, México 2 Radiaciones y Equipos de México, S.A. de C.V., México 3 CICATA, Instituto Politécnico Nacional, México Email: [email protected] Abstract In Mexico, previous studies performed to evaluate the image quality in digital mammography facilities show a poor image quality that is not compatible with mammography screening that may modify breast cancer mortality rate. The aim of the study is to evaluate the initial image quality in new full-field digital mammography (FFDM) units prior to use in patients to document that loss of image quality occurs later when quality assurance programs are not implemented, the absence of audits in mammography facilities, a small number of certified radiologists in mammography and absence medical physicists with training in mammography. We carried out an exploratory survey of 36 new (FFDM) units from a single manufacturer installed in several cities of the Mexican Republic with two types of target/filter combination (Mo/Mo and W/Rh). The tests were performed according to the manufacturer's quality control manual. The study found that the accuracy of the kVp is 2.93% ± 0.48 for Mo/Mo combination and 2.66% ± 0.51 (W/Rh); Measurements of the half-value layer (HVL) was = 0.38 ± 0.02 for Mo/Mo combination and HVL = 0.54 ± 0.01 for W/Rh. The calculated average glandular dose (AGD) was of 1.60 ± 0.16 for Mo/Mo and 1.16 ± 0.04 for W/Rh; signal-to-noise ratio (SNR) was 45.45 ± 1.83 for Mo/Mo and 54.81 ± 1.34 for W/Rh; contrast-to-noise ratio (CNR) was 10.33 ± 0.35 for Mo/Mo and 11.11 ± 0.28 for W/Rh. The scoring ACR phantom images with more frequency were 5 and 6 fibers, 4 specks groups and 4 masses. All mastography units exceed the image quality standards established by the ACR and FDA and the W/Rh combination achieved higher performance. However, if digital mammography facilities do not perform quality control programs using phantom, software and accessories from the manufacturer and are operated by a medical physicist with training in mammography the system may lose image quality over time and lack of Image quality increases after the warranty period expires. Keywords: Initial Image Quality; FFDM units. 77 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Medición del coeficiente de atenuación lineal de la cerveza Maria Daniela Ortiz Allende, Luis Enrique Amarillas Saliá, Diego Cano Sanchez, Hector Rene Vega-Carrillo Unidad Académica de Estudios Nucleares de la Universidad Autonoma de Zacatecas Calle Cipres #10, Fraccionamiento La Peñuela. 98060 Zacatecas, Zac., Mexico Buzones-e: [email protected], [email protected] Abstract Se determinó el coeficiente de atenuación lineal de la cerveza, mediante un experimento de transmisión con fuente de Cs137 y un espectrómetro de rayos gamma con detector de NaI(Tl) de 7.62 cm de diámetro y 7.62 cm de altura, usando geometría angosta. El espectro de altura de pulsos se acumuló por 1 minuto de tiempo vivo, se usaron 7 espesores de cerveza (0-6 cm). Mediante regresión lineal por mínimos cuadrados ponderados se determinó el coeficiente de atenuación lineal cuyo valor es µ=0.08290 ± 0.0061 cm-1. El coeficiente de atenuación lineal del agua es 8.6 % veces mayor que el de la cerveza, esta variación la atribuimos a los gases disueltos en la cerveza. Palabras clave: Coeficiente de atenuación lineal, cerveza, Cs137. 78 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Estudio de dosimetría utilizando maniquí de cabeza en exploraciones de tomografía computarizada Álvaro Mauricio Ladino Gómez1*, Arnaldo Prata Mourão1,2 1 Biomedical Engineering Center, Federal Center for Technological Education of Minas Gerais, Av. Amazonas, 5253 - Sala 113. CEP: 30421-169, Nova Suíça, Belo Horizonte, MG, Brazil 2 Department of Nuclear Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627, CEP: 31270-90, Pampulha, Belo Horizonte, MG, Brazil * Email: [email protected] Resumen La preocupación en las cantidades de dosis de radiación depositada en los pacientes, todavía es grande, debido a que los exámenes por Tomografía Computarizada (TC) son en la actualidad los que alcanza mayores niveles de radiación depositada en la población [1]. La legislación brasilera, regula los niveles de dosis depositada en pacientes se limita a estimar una cantidad máxima, dependiendo la región del cuerpo a ser expuesta [2]. Es por ello, que es necesario determinar la cantidad de dosis que se deposita en los pacientes dependiendo los protocolos de rutina que se emplean en los servicios de radiodiagnóstico y así, proponer una optimización de éstos bajo los principios referentes a limitación de dosis, optimización de la protección radiológica y por supuesto, la justificación de las prácticas [3]. Se realizaron experimentos para determinar el perfil de dosis para exámenes de rutina de cabeza en paciente adulto, utilizando un objeto simulador físico de polimetílmetacrilato (PMMA) en formato cilíndrico con 4 orificios periféricos y uno central. Se introdujeron tiras de película radiocrómica en cada uno de los orificios para registrar el perfil de dosis en cada región y así, determinar la cantidad de dosis depositada en todo el volumen del objeto simulador. Se utilizaron un tomógrafo General Electric de 64 canales, propio del servicio de radiología para tensiones de 80, 100 y 120 kV con corriente fija de 200 mA, encontrando niveles de dosis entre los 6,24 y 23,73 mGy. Fueron realizados análisis del ruido de las imágenes, encontrando que todas cumplen los parámetros aceptables en diagnóstico. Se propone un protocolo optimizado para exámenes por TC de cabeza con tensión de 80 kV para imágenes con índice de ruido de 0,5%. [1] BOLUS, N. E. NCRP Report 160 and What It Means for Medical Imaging and Nuclear Medicine. [S.l.]: J Nucl Med Technol, 2013. 41:255–260 p.. [2] Ministerio da Saúde, Portaria n° 45, 1 de junho de 1998. ANVISA, 1998, 48 p. [3] ZOETELIEF, J. et al. PATIENT DOSIMETRY FOR X RAYS USED IN MEDICAL IMAGING. Report 74. [S.l.]: ICRU, 2005. 18 p. Palabras clave: Dosimetría; Imágenes medicas; TC. 79 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Thermoluminescence properties of magnesium oxide doped with dysprosium and lithium obtained by solution combustion synthesis G. E. Sánchez-Ortega1,*, V. R. Orante-Barrón1, C. Cruz-Vazquez1, R. Bernal2 1 Departamento de Investigación en Polímeros y Materiales de la Universidad de Sonora Apartado Postal 130, Hermosillo, Sonora 83000 México 2 Departamento de Investigación en Física, Universidad de Sonora Apartado Postal 5-088, Hermosillo, Sonora 83190 México * Email: [email protected] Abstract Glycine molecule has a carboxylic acid group at one end and an amine group at the other end, both of which can participate in the complexation of metal ions. This “zwitterionic” character allows effective complexation with metal cations of different ionic size [1]. In the accordance with the above, it was possible to obtain magnesium oxide doped with trivalent dysprosium and lithium phosphor, for the very first time, by solution combustion synthesis (SCS) using glycine as fuel, in which a redox reaction at 500 °C was accomplished. Thermoluminescence glow curve obtained after exposure to beta radiation of these samples, displayed at least three maxima located at ~ 135 °C, ~ 227 °C, and ~ 317 °C. Results from experiments such as dose response and fading showed that annealed MgO: Dy3+, Li+ powder obtained by SCS is a promising material for radiation dosimetry applications. Complementarily, structural characterization such as scanning electron microscopy and Xray diffraction is presented. [1] Chick L.A. et al., (1990). Mater. Lett. 10: 7 Keywords: Thermoluminescence; Solution combustion synthesis; Magnesium oxide. 80 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Thermoluminescence of Mg doped Li2ZrO3 exposed to beta particles T. C. Hernández-Pérez 1, R. Bernal 2, C. Cruz-Vázquez 1, F. Brown 1, Ch. J. Salas-Juárez 1 1 Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora. Apartado Postal 130, Hermosillo, Sonora 83000 México. 2 Departamento de Investigación en Física, Universidad de Sonora. Apartado Postal 5-088, Hermosillo, Sonora 83190 México. Email: [email protected] Abstract Recently, we reported on the thermoluminescence (TL) and afterglow features of beta irradiated Li2ZrO3 phosphors. In this work, the effect of magnesium (Mg) impurity on the thermoluminescence response of Li2ZrO3 phosphors is studied. Li2ZrO3:Mg pellet shaped samples were synthesized by solid state reaction at 1000 ºC during 24 h in air atmosphere. Some samples were exposed to beta particles in order to investigate their thermoluminescence response. For Li2ZrO3, the TL glow curve is composed by a predominant intense peak with maximum at 164 °C, accompanied by less intense TL emission peaks at higher temperatures with maxima located at 248 °C, 315 °C and 382 °C. Adding Mg to Li2ZrO3 lead to diminished TL intensity and shift of the TL peaks to lower temperatures in regard to non-doped Li2ZrO3. The 2 mol% Mg doped Li2ZrO3 results show the linear dose response from 1 up to 100 Gy, higher stability and less fading. Keywords: Li2ZrO3:Mg; thermoluminescence; beta particles. 81 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. X ray quality control using thermoluminescent dosimeters David Alberto Rojas Solis1,*, Eduardo García Valencia1, Juan Azorín Nieto1, Enrique Gaona2 1 2 Universidad Autónoma Metropolitana Iztapalapa, CDMX, México Universidad Autónoma Metropolitana Xochimilco, CDMX, México * Email: [email protected] Abstract Locally made LiF:Mg,Ti + PTFE thermoluminescent dosimeters (TLD) were used for carrying out quality control tests in diagnostic X rays beams. Quality tests were performed measuring the air kerma and kerma rate values, the beam efficiency (repeatability and linearity), the coherence between the luminous field and the referring field of irradiation and half-value layer for a set of parameters. TLDs were previously characterized and calibrated for the same set of parameters. Measurements made with TLD were compared with those made with an electronic dosimeter (RADCAL). Results showed that the values of air kerma measured with TLD agree well with those made with the electronic dosimeter. The TLDs have revealed useful for the measures if the response to the dose is previously known for each set of beam parameters used for the irradiations. In other hand, the tests with the dosimeters can serve to evaluate the beams conditions and their repeatability. The evaluation results of coherence between the luminous field and the irradiation field demonstrated that the difference between the radiation field and the luminous field did not exceed 2% of the distance between the focal point and the film. Values obtained for halfvalue layer were satisfactory 82 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Thermally- and photo- stimulated luminescence of red eggshell irradiated by gamma of Co-60 E. Cruz-Zaragoza1,* G. Orduña Amado1, C. Furetta1, J. Marcazzó2, E. Bortolin3 1 Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México A.P. 70-543, 04510 Ciudad de México, México 2 Instituto de Física Arroyo Seco-CIFICEN, CONICET-UNCPBA Pinto 399, 7000 Tandil, Argentina 3 Instituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy * Email: [email protected] Abstract Food irradiation is a clean technological process to eliminate harmful bacteria and illnesses in commercial chicken eggshell. The identification methods [1-3] of the irradiated eggshell became important to the control doses in the product. Thermally and photo- stimulated luminescence properties were analyzed and also to identify irradiated red eggshell samples. The particles sizes at 74 and 149 µm eggshell powder were selected and followed they were washed by chloride acid at 37.1% concentration. The red eggshell was identified as calcium carbonate (CaCO3) by Scanning Electron Microscopy (SEM-EDS). The samples were gamma-irradiated between 8 Gy and 10 kGy. Three broad prominent glow-peaks at 110, 270 and 335 °C were observed in the experimental glow curves. The kinetics parameters were obtained by deconvolution assuming the general order kinetics model. The thermoluminescent (TL) glow curves allowed the identification of the irradiated eggshell at about 20 Gy. The linear dose-response was between 0.5 and 10 kGy. The photo-stimulated luminescence (PSL) signals give the irradiated samples identification with 5 kGy. The TL fading signals were very stable about 8% at 60 days after irradiation, while at the end of 7 days a strong decay (62 %) of the PSL signals was observed. The TL is a sensible method to detect the irradiated eggshell. [1] FAO/WHO, Codex Alimentarius Commission, Joint FAO/WHO Food Standards Programme, Codex Committee on Methods of Analysis and Sampling (Budapest) (2002). [2] Cruz-Zaragoza, E. et al., (2012). Radiat. Phys. Chem. 81: 1227-1231. [3] Della Monaca, S., et al., (2011). Radiat. Meas. 46: 816-821. Keywords: Thermoluminescence; PSL; Food irradiation; Eggshell; Gamma-ray. 83 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. ¿Antiguo o falso? El peritaje arqueológico con métodos luminiscentes Ángel Ramírez Luna1* y Peter Schaaf1 1 Laboratorio de Termoluminiscencia, Instituto de Geofísica, Universidad Nacional Autónoma de México. * Buzón-e: [email protected] Resumen Las implicaciones sobre la autenticidad o antigüedad de una pieza arqueológica es muy importante desde muchos puntos de vista, por ejemplo, las formas, iconografías, tipos de arcillas, desgrasantes y mineralogía entre otras características son muy buenos indicadores para entender la evolución alfarera, las relaciones sociopolíticas, los vínculos comerciales, los aspectos rituales, los periodos culturales y la funcionalidad de los artefactos entre muchas otras cosas. Si bien existe una gran cantidad de piezas arqueológicas de las cuales se conoce el contexto del que provienen, es decir, hay registros del trabajo de campo y del proceso de excavación, existen muchas piezas de las cuales se desconoce el contexto, esto hace dudar de la legitimidad de la pieza o dicho de otra manera, de su antigüedad, este tipo de piezas sin contexto generalmente se encuentran en museos, colecciones privadas, en casas de subastas de arte e incluso en el mercado negro. En otro sentido, el valor económico de piezas arqueológicas vistas como piezas de arte puede llegar a ser muy alto, esto es un detonante para el mercado negro de piezas y la falsificación de estas. Por ejemplo, es común en México encontrar piezas falsas en colecciones que se conformaron hace más de un siglo donde el aspecto económico fue el motivo por el que fueron elaboradas. La falsificación de piezas complica en análisis visual y provoca que arqueólogos y ceramistas en ocasiones emitan juicios erróneos sobre la antigüedad o autenticidad de piezas arqueológicas, esto debido a los sofisticados procesos de manufactura actuales que recrean las técnicas antiguas adem s de “envejecer” artificialmente las piezas, la iconografía o motivos también pueden ser modificados e incluso inventados, creando incertidumbre en quienes estudian e interpretan desde un punto de vista académico-cultural estas piezas. La datación por termoluminiscencia (TL) es un método que además de proporcionarnos la edad de una pieza arqueológica[1] nos da información del material analizado como la concentración de radioisótopos en la arcilla y la forma de la curva TL, estos elementos junto con la fluorescencia de luz ultravioleta que es una técnica muy empleada en el análisis y caracterización de bienes culturales[2] dado que los materiales pueden tener distintos patrones de comportamiento ante la luz UV, nos dan elementos para determinar si una pieza arqueológica es antigua o de reciente fabricación, es decir, falsa. En este trabajo se presentan algunos ejemplos del análisis de piezas arqueológicas y los procedimientos que se están implementando en el Laboratorio de Termoluminiscencia de la Universidad Nacional Autónoma de México para realizar peritaje arqueológico. [1] Aitken, M., (1985). Thermoluminescence Dating, Oxford Academic Press, London [2] Espinoza, F. y Rivas V., (2011). Conserva, No. 16. Palabras clave: Peritaje arqueológico; Termoluminiscencia; Fluorescencia de luz UV; Arqueometría. 84 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Evidencia por termoluminiscencia de ocupaciones posteriores a la caída del sitio arqueológico El Tajín, México Ángel Ramírez Luna1*, Elizabeth Galeana Cruz2, Peter Schaaf1 Laboratorio de Termoluminiscencia, Instituto de Geofísica Universidad Nacional Autónoma de México. Instituto Nacional de Antropología e Historia, México. * Buzón-e: [email protected] Resumen El Tajín, Veracruz, México, es un sitio arqueológico precolombino considerado capital del imperio Totonaca, su cronología se estima iniciando en el año 350 d.C y su caída en el año 1100 d.C., llegando a su apogeo en el periodo epiclásico entre los años 600 y 900 d.C., se sospecha que tuvo ocupaciones posteriores a su caída, sin embargo, no existen evidencias de materiales culturales que soporten dicho planteamiento.El cauce de un arroyo que bordea El Tajín fue dejando al descubierto un par de elementos que en 2012 fueron identificados por personal del INAH, lo cual motivó su verificación, registro y posteriormente su intervención sistemática. En campo se lograron identificar los fragmentos de una olla dentro de uno de los elementos, al analizar la vasija macroscópicamente se definió como de uso doméstico del tipo Café erosionado, sin embargo, la forma y el estilo no permitieron considerarla como material diagnóstico temporal para poder ubicarla dentro de la secuencia ocupacional de El Tajín, del 350 al 1100 d. C. [1] y porque se siguen utilizando formas semejantes en la actualidad[2] . Esta falta de claridad otorgada por los materiales cerámicos, el uso actual de la forma de la vasija, y la posibilidad de corresponder a una ocupación posterior a la decadencia de El Tajín, radica la importancia del análisis más exhaustivo de esta olla. La caracterización del fragmento de olla analizada se conformó por su descripción física, por su datación por el método de termoluminiscencia, por el análisis químico de sus residuos orgánicos e inorgánicos además de su análisis mineralógico por microscopía electrónica de barrido realizando espectrometría de energía dispersada de rayos X (EDS). La datación por termoluminiscencia arrojo una edad relativa de 1760±25 d.C. esto confirma la existencia de ocupaciones posteriores a la caída de El Tajín, el análisis mineralógico muestra que la arcilla contiene un 60% de plagioclasa, 15% de calcita, 5% de cuarzo principalmente. Del análisis químico de residuos orgánicos e inorgánicos se infiere que muy posiblemente la olla se utilizó como contenedor de agua por la gran cantidad de carbonatos presentes corroborando la descripción morfológica que se realizó de la olla como contenedor, adicionalmente la baja concentración de proteínas y la falta de evidencia de haberse expuesto al fuego, descarta su uso en la preparación de alimentos o para contener alimentos con alto contenido proteico como por ejemplo la carne. Actualmente se siguen caracterizando materiales cerámicos de diferentes periodos de El Tajín, esto con el objetivo de correlacionar la mineralogía con la procedencia, las edades absolutas para establecer la cronología en la seriación cerámica e identificar la morfología cerámica con su función a través del análisis químico de residuos. Estas edades cerámicas son las primeras dataciones absolutas en esta región y sobre materiales totonacas, esperando sea la base de las dataciones relativas en la zona norte del Golfo de México. [1] Pascual, A., (2006). El Tajín: en Busca de los Orígenes de una Civilización México, UNAM-IIE, INAH. [2] Galeana, E., et al, (2014), Informe técnico, manuscrito, Archivo Técnico de la Zona de Monumentos Arqueológicos El Tajín, del Centro INAH Veracruz y de la Coordinación Nacional de Arqueología, INAH. Keywords: Datación cerámica; Termoluminiscencia; Tajín; Cronología. 85 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Dose-response characterization of gadolinium-infused polymer PAGAT dosimetry aimed at dose enhancement assessment. M. Santibáñez1,2,*, Y. Guillen2, D. Chacón3,4, R. Figueroa 1,2, M. Valente1,2,3,5 1 Departamento de Ciencias Físicas, Universidad de La Frontera, F. Salazar 01145, Temuco, Chile. 2 Centro de Física e Ingeniería en Medicina - CFIM, Universidad de La Frontera, Temuco, Chile. 3 Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Universidad Nacional de Córdoba, Av. M. Allende s/n, Argentina. 4 Departamento de Física, Universidad Nacional, Heredia, Costa Rica. 5 Instituto de Física E. Gaviola – CONICET, Argentina. * Email: mauricio.santibanez @ufrontera.cl Abstract Nowadays, infusion of high atomic number elements within biological tissue represents one of the most promising mechanisms aimed at imaging and therapeutic medical tasks, like tumor targeting, real-time monitoring and local dose enhancement. It is well known that Gadolinium has proven to be an excellent contrast agent for traditional absorption contrast medical imaging. However, Gd is being considered for different medical tasks regarding local dose enhancement, as preliminary reported for brain tumors treatment [1]. This work reports on the effects of infusing PAGAT [2] polymer gel dosimeters with gadolinium aimed at obtaining an integral stable dosimetry system capable of suitable mixed field dose decomposition in order to assess therapeutic local dose enhancement due to the selective uptake of high atomic number elements, such as Gd, in biological tissues. In this context, capability to elaborate stable and still dosimetric reactive solution is the first step to accomplish the purposed goal of achieving reliable and accurate measurements of local dose enhancement due to Gd presence. A novel dosimetry system was prepared following similar synthesis as for PAGAT dosimeter, but including suitable adaptations to add Gdbased solutions (Omniscan®) obtaining a final stable material whose dose-response was carefully characterized, along with its chemical properties. [1] Prezado ,Y. et al., (2009). Med. Phys. 36: 3568-3574. [2]Vedelago, J. et al., (2016). Rad. Meas. 91: 54-64. Keywords: Dose enhancement; PAGAT gel dosimetry; Dose-response characterization. 86 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Estimation of patient Effective doses in positron emission tomography and computed tomography in Kuwait Meshari Alnaaimi1,*, Mohammed Alkhorayef 2, 3, Abdelmoneim Sulieman4, Musa Alduaij1, Talal Mohammedzein 1, David Bradley3,5 1 Department of Nuclear Medicine, Kuwait Cancer Control Center, Shwiekh, Kuwait Department of Radiological Sciences, College of Applied Medical Sciences, King Saud University, PO Box 10219, Riyadh 11433, Saudi Arabia 3 Department of Physics, University of Surrey, Guildford, Surrey, UK 4 Radiology and Medical Imaging Department, Prince Sattam Bin Abdulaziz University, College of Applied Medical Sciences,Saudi Arabia 5 Sunway University, Institute for Health Care Development, Jalan University, 46150 PJ, Malaysia 2 * Email: [email protected] Abstract The combination of positron emission tomography (PET) with Computed tomography (CT) has been used to diagnose and evaluate many clinical conditions. However, both imaging modalities expose the patients to significant radiation dose from ionizing radiation. The radiation dose from both the positron emitters (e.g.18F) and from X-rays used PET/CT imaging results in high patient dose. Therefore, there is a massive need to assess and optimize the radiation dose to the patients during PET/CT procedures. The objective of this study is to evaluate the patients radiation dose and radiation risks and to establish diagnostic reference levels (DRL) for PET/CT procedures in Kuwait. A total of 220 patients doses were investigated. The patients were scanned using a general electric (GE) discovery 710 PET/CT scanner at the department of nuclear medicine in Kuwait cancer control center (KCCC), Kuwait. The patients effective dose were estimated using the administered activity. The mean patients effective dose was estimated using patient exposure parameters in ImPACT software. The mean and range of the administered activity is 222 MBq (6.0 mCi) per procedure, based on patient body mass index (BMI). The range of patients' effective doses per procedure was 5 - 18 mSv. The radiation risk per procedure is 1x10-5 per procedure. Patient doses depend on the size of patient, the type of scanner, the imaging protocol and reconstruction method used. Effective doses considered low compared with previous studies. Proper justification and radiation dose optimisation are required for further dose reduction. [1] Quinn B (2016) BMC medical imaging 16:41 [2] Czernin. J. (2004) Nuc Med 45.1s-3s. Keywords: PET/CT; Radiation risk; Effective dose; Nuclear medicine. 87 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Characterization and performance tests of a new OSL/TL dosimeter for individual monitoring Anna LMC Malthez1,*, Marcelo B Freitas², Elisabeth M Yoshimura³, Nancy K Umisedo³, Vera LSN Button4 Department of Physics, Federal University of Technology – Parana; Curitiba-PR, Brazil Health Informatics Department, Federal University of Sao Paulo; Sao Paulo-SP, Brazil 3Nuclear Physics Department, University of Sao Paulo; Sao Paulo-SP, Brazil 4 Biomedical Engineering Department, Campinas State University; Campinas-SP, Brazil 1 2 * Email: [email protected] Abstract Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) techniques are used to assessment of occupational doses in individual monitoring (IM). In Brazil, the accreditation body responsible for certification process in IM (CASEC/IRD/CNEN) established performance tests and criteria for dosimetric systems based on TL and photographic techniques (IRD – RT 002.01/95)[1]. Those are similar to tests and criteria present in international standards for passive dosimetric systems, like IEC 62387-1[2], but it is restrict to two techniques. In this work, we propose a new personal dosimeter based on the combination of TL and OSL detectors (BeO/Al2O3, BeO/CaSO4 and Al2O3/LiF) employing the advantages of both techniques. The new OSL/TL dosimeter was tested for assessment of doses in simulated and real situations of exposure. In additional, Brazilian national performance tests adapted to the new dosimeter were done and those dosimeters were also submitted to criteria and performance tests of international standard for passive dosimetric systems. The results shows the advantages of combined TL and OSL techniques with different detectors materials, which allows corrections about energy and incidence of radiation without attenuation filters, possibility of to evaluate simultaneously single and accumulated doses and triple check of the values. Further the results of performance tests are consistent with national and international regulatory requirements showing the viability of to apply the new dosimeter to the assessment of doses in IM. [1] Instituto de Radioproteção e Dosimetria (IRD/CNEN). IRD – RT n. 002.01/95 - Desempenho de Sistemas de Monitoração Individual: Critérios e Condições (1995). [2] IEC. BS EN IEC 62387-1:2012 - Radiation protection instrumentation. Passive integrating dosimetry systems for environmental and personal monitoring. General characteristics and performance requirements (2012). Keywords: Individual Luminescence Monitoring, Thermoluminescence, 88 ISSSD 2017 Book of abstracts Optically Stimulated ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Thermoluminescence properties of new BaZrO3 phosphors exposed to beta particle irradiation Ch. J. Salas-Juárez1*, C. Cruz-Vázquez1, R. Aviles-Monreal2, R. Bernal2 1 Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora. Apartado Postal 130, Hermosillo, Sonora 83000 México. 2 Departamento de Investigación en Física, Universidad de Sonora Apartado Postal 5-088, Hermosillo, Sonora 83190 México * Email: [email protected] Abstract Due to the increasing use of ionizing radiations, it is necessary to monitor the radiation fields and exposure doses in facilities in which they are used. Thermoluminescent dosimetry has been extensively studied for the measurement of absorbed radiation dose [1]. Currently, there are several commercially available thermoluminescent dosimeters (TLDs), but not all of them meets all existing needs, such as wide range of linear doses, chemical stability, non-toxicity, among others [1]. Barium zirconate (BaZrO3) has attracted attention due to its interesting properties, such as thermomechanical [2], electric, dielectric and optical features [3]. BaZrO3 has been studied for photoluminescence applications; however, there is no previous study related to thermoluminescent dosimetry. In this work, we present the synthesis and thermoluminescence properties of BaZrO3 synthesized by the solid-state reaction method. Pellet shaped samples were annealed to 1000 ° C for 24 h in an air atmosphere. The phosphors were then irradiated to 25 Gy of beta particles. The TL glow curves showed two maxima, located at 133 °C and at 220 °C, respectively. The irradiationTL readout cycles showed a variation of 5% between the first and the tenth cycle. Some samples were exposed to doses in the range from 0.5 -1024 Gy showing an increase in intensity as a function of absorbed dose. Preliminary results show that the synthesized phosphors can be used as dosimeters of ionizing radiation. [1] Kortov, V. (2007). 42: 576-581. [2] Parganiha, Y. et al., (2015). Superlat Microstru., 88: 262-270 [3] Khirade, P.P. et al., (2017). J Alloys Comp., 691: 287-298 Keywords: Thermoluminesce, BaZrO3, Beta particle 89 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Contribution of the MWCNT-ZrO2 addition on the dosimetric properties of PVDF Esther Lorrayne Machado Pereira1, Adriana de Souza Medeiros Batista2*, Neiriene Alves1, Arno Heeren de Oliveira1, Fabiola A. S. Ribeiro3, Adelina P. Santos3, Luiz Oliveira de Faria3 1 Departmento de Engenharia Nuclear, Universidade Federal de Minas Gerais Belo Horizonte, MG, Brazil 2 Departmento de Anatomia e Imagem, Universidade Federal de Minas Gerais Belo Horizonte, MG, Brazil 3 Centro de Desenvolvimento da Tecnologia Nuclear, Comissão Nacional de Energia Nuclear Belo Horizonte, MG, Brazil * Email: [email protected] Abstract PVDF is a homopolymer liner known for its ferroelectric properties, used in industrial and medical applications [1]. In recent years, PVDF and copolymers have been evaluated as high-dose dosimeters using Fourier Transform Infrared Spectroscopy (FTIR), UV-Vis spectroscopy and Differential Scanning Calorimetry (DSC) techniques [2,3,4]. In order to increase the radioresistation to the irradiation process and increase the dosage range applicable to the PVDF-based dosimeters for this work, the dosimetric properties of the PVDF / MWCNT-ZrO2 composite were tested. The samples were submitted to a Co-60 source at doses ranging from 100 to 2750 kGy and showed a ratio of absorbed dose to absorbance at 1750 cm-1 and 1730 cm-1 in the FTIR spectra. Analysis of DSC and Scanning Electron Microscopy (SEM) demonstrated increased resistance to the radiation process compared to pure irradiated PVDF sample in the same doses, following the values of latent heat of crystalline fusion and the presence of sphurilite formation in the polymer matrix. The results indicate that the PVDF / MWCNT-ZrO2 composite adds resistance to PVDF thus improving its dosimetric properties. [1] Lovinger, A.J. (1983). Science, 220: 1115-1126. [2] Liz, O. S. R.; et al., (2011). Nucl. Instr. Meth. Phys. B, 269: 2819-2823. [3] Medeiros, A.S. & Faria, L.O. (2008). Nucl. Instr. Meth. Phys. B 587: 315-318, [4] Batista, A.S.M. & Faria, L.O. (2017). Radiat. Phys. Chem. Doi: 10.1016/j.radphyschem.2017.02.040. Keywords: High Dose Dosimetry; PVDF; MWCNT-ZrO2. 90 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Study on photon interaction with normal and cancerous tissues V. P. Singha, N. M. Badigera and H. R. Vega-Carrillob a b Department of Physics, Karnatak University Dharwad, 580003, India UnidadAcademica de EstudiosNucleares, Universidad Autonoma de Zacatecas C. Cipres 10, Fracc. La Penuela, 98060 Zacatecas, Zac.Mexico Email: [email protected] Abstract In the present investigation, photon interaction properties of normal and cancerous tissues using mass energy absorption coefficients, effective atomic numbers and electron densities were discussed. The photon interaction parameters were computed using mass energy absorption coefficients of individual elements. Also, effective atomic numbers were compared with photon transmission technique. The investigated results would be very useful medical applications. Keywords: Cancerous tissues; Photon; Effective atomic number; XCOM. 91 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Base de datos INIS soporte informativo para las investigaciones de dosimetría de estado sólido Irayda Oviedo Rivero1*, Belkis Year López1, Carolina Lugones Castillo2, Lauren Elías Hardy3 1 Centro de Gestión de Información y Desarrollo de la Energía (Cubaenergía), La Habana, Cuba 2 Centro de Protección e Higiene de las Radiaciones (CPHR), La Habana, Cuba 3 Instituto Superior de Tecnologías y Ciencias Aplicadas (InSTEC), La Habana, Cuba * Buzón-e: [email protected] Abstract La dosimetría de estado sólido ha sido ampliamente usada; en especial el método de termoluminiscencia (TL). En algunos casos resulta ser la herramienta dosimétrica para resolver las grandes incertidumbres [1], por eso es de vital importancia mantener su buena salud tanto en la investigación como en nuevas aplicaciones [2]. La BD INIS del Sistema Internacional de Información Nuclear que coordina el Organismo Internacional de Energía Nuclear (OIEA) es el sistema líder sobre usos pacíficos de la energía nuclear con más de cuatro millones de registros. El Centro de Protección e Higiene de las Radiaciones (CPHR) gestiona anualmente dos ediciones del Curso Fundamentos de la Protección Radiológica, Cubaenergía como centro INIS imparte el módulo gestión de información. En este trabajo conjunto se han realizado diferentes estudios métricos (búsqueda, tratamiento estadístico, tabulación, visualización y presentación de informe) que han servido de soporte para la toma de decisiones en cuanto a diseño y desarrollo de proyectos de investigación. En el presente trabajo se expone la experiencia relativa a dosimetría de estado sólido. Los resultados muestran las principales áreas abordadas (Dosimetría y Protección Radiológica725, Instrumentación-283 y Ciencia de los Materiales-213; la tipología documentaria (artículos de revista- 2112; misceláneas 816; libros-48). Otras variables estudiadas fueron: producción científica, coautorías; instituciones y países de origen y citaciones. Se concluye que la BD INIS constituye un soporte informativo para la dosimetría de estado sólido, aunque debe incrementar el número de registros de patentes y tesis. [1] Velasco, V.R.A.E. Validacion de un sistema de braquiterapia hdr para pacientes con cancer cervico-uterino. 2011. Tesis doctoral. [2] Bartlett, D.T. (2008). Rad. Meas., 43: 133-138. Keywords: Solid state dosimetry; Metrics studies; Knowledge management; Information management. 92 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Photon absorption of calcium phosphate based teeth biomaterials in diagnostic radiology V. P. Singha, N. M. Badigera, H. O. Tekinb, Umit Karac, H. R. Vega-Carrillod, M. A. Fernandes Zenobioe a Department of PhysicsKarnatak University, Dharwad, 580003, India Uskudar University, Vocational School of Health Services, Radiotherapy 34672, İstanbul, Turkey c Suleyman Demirel University, Vocational School of Health Services, Medical Imaging 32100, Isparta, Turkey d UnidadAcademica de EstudiosNucleares, Universidad Autonoma de Zacatecas C. Cipres 10Fracc. La Penuela, 98068 Zacatecas, Zac.Mexico e Development Center of Nuclear Technology- CDTN/CNEN Avenida Presidente Antônio Carlos 6.627Campus UFMG 31270-901Belo Horizonte, Brazil. b Email: [email protected] Abstract In the present investigation, photon absorption computed for four dental calcium phosphate based biomaterials for diagnostic radiology qualities. Mass energy absorption coefficients, effective atomic number and photon energy absorption buildup factors were computed using NIST data and GP fitting method. The photon energy and chemical compositions dependency is analyzed for mass energy absorption coefficients, effective atomic number and photon energy absorption buildup factors. The study would be very useful for diagnostic radiology of teeth and exposure control practices. Keywords: Biomaterials; Teeth; Buildup factors; Effective atomic number; NIST. 93 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Síntesis y caracterización de nano cristales de fluoruro de litio dopados con plata (LiF: Ag) Bernardo Rafael Rosario Universidad Autónoma de Santo Domingo Código postal 10103, República Dominicana Buzón-e: [email protected] Resumen La termoluminiscencia (TL) es la emisión de luz por ciertos materiales al ser calentados por debajo de su temperatura de incandescencia, habiendo sido previamente expuestos a un agente excitante tal como las radiaciones ionizantes. El fluoruro de litio (LiF) es el material termoluminiscente usado en la elaboración de dosímetros TL-100. ¿Cuáles características Morfológicas (Tamaño, Cristalinidad) poseen los nanocristales del fluoruro de litio (LiF) puro al ser dopados con plata (Ag) por el método de precipitación? El objetivo de este estudio fue sintetizar y caracterizar los nanocristales de LiF dopados con Plata (Ag) en concentraciones de 0.02%, 0.04%, 0.06%, 0.08%, 0.1% y 0.2%. Las muestras fueron sintetizadas usando como reactivos; Agua (destilada), Fluoruro de amonio ( NH 4 F ), Cloruro de Litio ( LiCl ), Nitrato de plata ( AgNO3 ). Y materiales tales como; balanza de precisión de 0.1 mg, espátulas, probeta, agitador magnético, vaso de precipitado, matraz aforado, bureta, pinza de bureta, llave, varita de agitación magnética. En el proceso de caracterización usamos un difractómetro de rayos x (XRD) con el que obtuvimos el espectro de difracción de rayos x con picos bien definidos que son característicos del LiF. Usando la ecuación de Scherrer calculamos los tamaños de los nanocristales que van desde 17.17 nm hasta 41.64 nm. El promedio es de 29.71 nm. Este estudio demuestra que es posible sintetizar el LiF usando nuevos materiales dopantes. 94 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Characterization and performance tests of a new OSL/TL dosimeter for individual monitoring Anna LMC Malthez1,*, Marcelo B Freitas², Elisabeth M Yoshimura³, Nancy K Umisedo³, Vera LSN Button4 Department of Physics, Federal University of Technology – Parana; Curitiba-PR, Brazil Health Informatics Department, Federal University of Sao Paulo; Sao Paulo-SP, Brazil 3Nuclear Physics Department, University of Sao Paulo; Sao Paulo-SP, Brazil 4 Biomedical Engineering Department, Campinas State University; Campinas-SP, Brazil 1 2 * Email: [email protected] Abstract Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) techniques are used to assessment of occupational doses in individual monitoring (IM). In Brazil, the accreditation body responsible for certification process in IM (CASEC/IRD/CNEN) established performance tests and criteria for dosimetric systems based on TL and photographic techniques (IRD – RT 002.01/95)[1]. Those are similar to tests and criteria present in international standards for passive dosimetric systems, like IEC 62387-1[2], but it is restrict to two techniques. In this work, we propose a new personal dosimeter based on the combination of TL and OSL detectors (BeO/Al2O3, BeO/CaSO4 and Al2O3/LiF) employing the advantages of both techniques. The new OSL/TL dosimeter was tested for assessment of doses in simulated and real situations of exposure. In additional, Brazilian national performance tests adapted to the new dosimeter were done and those dosimeters were also submitted to criteria and performance tests of international standard for passive dosimetric systems. The results shows the advantages of combined TL and OSL techniques with different detectors materials, which allows corrections about energy and incidence of radiation without attenuation filters, possibility of to evaluate simultaneously single and accumulated doses and triple check of the values. Further the results of performance tests are consistent with national and international regulatory requirements showing the viability of to apply the new dosimeter to the assessment of doses in IM. [1] Instituto de Radioproteção e Dosimetria (IRD/CNEN). IRD – RT n. 002.01/95 - Desempenho de Sistemas de Monitoração Individual: Critérios e Condições (1995). [2] IEC. BS EN IEC 62387-1:2012 - Radiation protection instrumentation. Passive integrating dosimetry systems for environmental and personal monitoring. General characteristics and performance requirements (2012). Keywords: Individual luminescence. monitoring; Thermoluminescence; 95 ISSSD 2017 Book of abstracts Optically stimulated ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Sonido focalizado: Terapia oncológica para tejido transformado Citlalic Elena Mares, Teodoro Córdova, Angelica Hernández División de Ciencias e Ingenierías, Universidad de Guanajuato campus León Loma del Bosque N. 103, Lomas del Campestre, 37150 León, GTO, Mex. Buzón-e: [email protected] Resumen La inquietud del ser humano conlleva observar y ser crítico a través de sus sentidos, en particular una perturbación en el medio causa vibración que pueden ser registradas por el sentido del oído a través de tímpano, si lo que produce está en la frecuencia del sonido audible. La distinción del sonido de las otras formas de trasferencia de energía es que las ondas del mismo involucran rápidamente el regreso progresivo de desplazamientos o vibraciones de las moléculas en el medio que se propaga. En este trabajo, se hizo un barrido de frecuencias desde el infrasonido hasta el ultrasonido en plantas de diferentes tipos con diferentes grosores y dos personas a fin de encontrar la resonancia de cada uno de ellos y compararla con las resonancias registradas en texto, lo anterior permitió evaluar el efecto secundario del sonido focalizado en el tejido de las hojas y en particular de las personas. Consideramos que se tiene potencial de esta modalidad de sonido focalizado si es a la frecuencia de resonancia del tejido transformado como medio de terapia oncológica sin afectar a las células vecinas. Palabras clave: Sonido focalizado; Tejido transformado; Resonancia. 96 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Determinación de plata en sustratos biológicos Sandra Judith Castañeda Palafox1,*, José de Jesús Bernal-Alvarado1, Daniel Jiménez Mendoza1, Teodoro Córdova Fraga1 1 División de Ciencias e Ingenierías Campus León, Universidad de Guanajuato Loma del Bosque No. 103 Col. Lomas del Campestre, C.P. 37150, León Gto. México. * Email: [email protected] Resumen La técnica de fluorescencia de rayos-X por energía dispersiva (EDXRF), es un método analítico que nos permite estudiar de manera cualitativa y cuantitativa la composición elemental de diversos materiales. Además es un método rápido, exacto y no destructivo y se ha aplicado en diferentes ramas, ya que sus aplicaciones van desde la investigación científica hasta la industrial [1-4]. En este trabajo se realizan pruebas con plata coloidal en gel de agarosa. La agarosa es un polisacárido extraído de algas marinas, soluble en agua, no tóxico y por ser un producto natural forma una matriz inerte, lo cual lo hace idóneo para la simulación de un sustrato biológico. Se realiza una preparación al 0.6% de agarosa en agua destilada y se analizaron diversas muestras constituidas por un mililitro aproximado de gel de agarosa y gotas de plata coloidal en distintas cantidades. Se hace un análisis cualitativo y cuantitativo a cada una de estas muestras. Los resultados de este análisis, permite medir el incremento a la concentración de plata en cada una de las muestras, por lo que esto indica que la plata si puede ser detectada en este sustrato mediante la técnica de EDXRF. Los resultados de este trabajo permiten establecer una metodología para la cuantificación de trazas metálicas en muestras biológicas de interés biomédico. [1] Schiavon, N. (2016). Spectrochimica Acta Part B 123: 42-46. [2] Kinoshita, H. (2013). Foren. Sci. Int., 227: 103-105. [3] Doyle, A. (2015). Fuel 162: 39-46. [4] Li, X & Yu, Z. (2016). Appl. Rad. Isot., 111: 45-49. [5] Brouwer, P. TEORÍA DE FRX, Primera Edición, capitulo 5, pp. 49, (2010). Palabras clave: Sustrato; Agarosa; Plata. 97 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. H*(10) debida a la radiación dispersada en un TomoLINAC Hector Rene Vega-Carrillo1,*, Angélica Esparza Hernández1, Mayra Guadalupe García Reyna2, Eric Reyes Rivera3,4, Teodoro Rivera5 1 Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas C. Ciprés 10, Fracc. La Peñuela. 98060 Zacatecas, Zac. México. 2 ITESM – Campus Zacatecas. Guadalupe, Zac. 3 División de Ciencias e Ingenierías Campus León, Universidad de Guanajuato Loma del Bosque No. 103, Col. Lomas del Campestre. 37150, León Gto. México. 4 UNEME-Oncología. Guadalupe, Zac. México. 5 CICATA-IPN, Unidad Legaria. Ciudad de México. México * Buzón-e: [email protected] Resumen Con el fin de determiner la dosis equivalente ambiental (H*(10)), debida a la radiación que se dispersa sobre el cuerpo de un paciente, se usaron dosímetros termoluminiscentes (TLD 100) en torno a un acelerador lineal para tomoterapia de 6 MV. En la tomoterapia, los haces de rayos X se aplican en cortes pequeños conformando el perfil del tumor [1]. Aquí, el cabezal se mueve en forma controlada alrededor del cuerpo del paciente y el haz se aplica en cortes cuyo espesor y tiempo de exposición se programan acorde a la morfología del tumor y el ángulo de ataque. Mientras se hace el tratamiento el cuerpo del paciente se desplaza y el haz se aplica en forma helicoidal [2]. Esta tecnología, como todas las que usan la intensidad modulada, tiene el inconveniente de que el blindaje del búnker aumenta considerablemente [3] y para su diseño se usan parámetros validados para los linacs convencionales [4]. Con el fin de determinar la H*(10) debida a la radiación dispersada se hicieron mediciones en la vecindad del isocentro, mientras el haz de fotones de 6 MeV se hacia incidir sobre un fantoma. También, se colocaron TLDs en los muros del bunker que permanecieron durante 7 días, donde aproximadamente se atendieron 50 pacientes/día. La H*(10) en puntos cercanos al isocentro se observe una distribución angular causada por la forma del fantoma. En los muros del bunker la mayor H*(10) se observó en las barreras primarias. En el laberinto, se observó el impacto de la radiación dispersada al medir un mayor valor de la H*(10) en el muro más alejado del isocentro en comparación con el punto ubicado más próximo a éste. [1].- Murray, L.J. & Robinson, M.H. (2016). Medicine 44: 10-14. [2].- Chargari, C. et al., (2016). Can. Metas. Rev., 35: 277-288. [3].- Biltekin, F. et al., (2015). Tech. Can. Res. Treat., 15: 560-565. [4].- Balog, J. et al. (2005). Med. Phys., 32: 710-719. Palabras clave: Dosis equivalente ambiental; Tomoterapia; LINAC; TLDs; Radiacion dispersada. 98 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Dosimetric characterization of small photons beams of a novel linear accelerator using EDGE diode detector A. Almonte, G. Polanco, E. Sánchez Department of Medical Physics, Institute of Oncology “Dr. Heriberto Pieter” Santo Domingo, Dominican Republic. E-mail: [email protected] Abstract UNIQUE (Varian Medical Systems, Palo Alto, California) is one of the latest generation of single low-energy linear accelerator (linac) with advanced features introduced in the clinical practice. The first application of UNIQUE for clinical radiotherapy occurred in 2012. Reports about its mechanical and dosimetric performances are extremely scarce in specialized and technical literature. This linac has the capability for intensity modulation radiation therapy (IMRT) and radiosurgery (SRS) treatments that recently were commissioned in our Institute. The aim of the present contribution was to measure the main dosimetric quantities of small fields produced by UNIQUE and evaluate its matching with the corresponding dosimetric data of one 21EX conventional linear accelerator (Varian) in operation at the same center. The second step was to evaluate comparative performance of the EDGE diode detector and the PinPoint micro-ionization chamber for dosimetry of small fields. UNIQUE is configured with MLC (120 leaves with 0.5 cm leaf width) and a single low photon energy of 6 MV. Beam data were measured with scanning EDGE diode detector (volume of 0.019 mm3), a PinPoint micro-ionization chamber (PTW) and for larger fields (≥ 4x4cm2) a PTW Semi flex chamber (0.125 cm3) was used. The scanning system used was the 3D cylindrical tank manufactured by Sun Nuclear, Inc. The measurements of PDD and profiles were done at 100 cm SSD and 1.5 depth; the relative output factors were measured at 10 cm depth. PDD and the profile data showed less than 1% variation between the two linear accelerators for 2x2 cm2 and 5x5 cm2 field sizes. The output factor differences were less than 1% for 3x3 cm2 and 10x10 cm2 field sizes, and less of 1.5 % for 1.5x1.5 cm2 and 2x2 cm2 field sizes. The dmax value of the EDGE diode detector, measured from the PDD, was 8.347 mm for 0.5x0.5 cm2 for UNIQUE. The performance of EDGE diode detector was comparable for all measurements in small fields. Flatness and symmetry were measured and compared. UNIQUE linear accelerator show similar dosimetrics characteristics as conventional 21EX Varian linear accelerator for small, medium and large field sizes. EDGE detector shows good performance in measuring dosimetrics quantities in small fields typically used in IMRT and radiosurgery treatments. Keywords: Small field dosimetry; EDGE diode detector; Beam matching; SRT; IMRT. 99 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Novel media and mechanisms applied to radiation dosimetry David Bradley Department of Physics, University of Surrey, Guildford, GU2 7XH, UK Institute for Healthcare Development, Sunway University, 46150 PJ, Malaysia Abstract We discuss development of novel dosimetric media, specifically Ge-doped silica and carbon nanontubes (CNTs). The defects giving rise to electron trapping are of particular interest, readout of the radiation sensitive signal being obtained throu gh use of one or other of the related stimulated luminescence phenomenon, thermoluminescnce (TL) and radioluminescence (RL). Working with CNTs, use has also been made of photoelectron spectroscopy (XPS), a surface-sensitive technique which provides interrogation of bonding rearrangements in the irradiated material. During the course of studies, various manipulations of the media have been made in an attempt to improve their radiation sensitivity, as an example in TL studies starting from simple use of standard Ge-doped silica telecommunication fibres (SMF), through to tailor-made Ge-doped flat fibres (FFs) as well as Ge-doped photonic crystal fibres (PCF) co-doped with boron. The FFs and PCFs are formed of capillaries that at high temperatures and under vacuum are made to collapse inwards, the internal walls fusing and generating strain-related defects. Currently in use of such glassy media, we have made successful measurements of terrestrial natural radiation dose (eg 1 or 2 mGy per year), the very low doses of dental radiography (~ 10s µGy delivered in a few ms), the tens of Gy doses of radiotherapy, through to 10s of kGy used in radiation processing. For the CNTs, developments point to their use in skin dosimetry. In use of RL, we have compared the signal originating from Ge-doped silica optical fibres and commercial nanoDot Al2O3:C dosimeters, the RL signal being guided through PMMA optical fibre cables to obtain real-time measurements. For the Ge-doped fibre the manifest absence of an appreciable memory effect or afterglow, favours its preferential use in realtime evaluations. 100 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Exotic dosimetric techniques Oswaldo Baffa Department of Physics-FFCLRP-USP Ribeirao Preto, SP, Brazil Abstract Dosimetric techniques somehow measure the energy deposited in a given medium through the effects of ionizing radiation on it. Ionizing radiations can be electromagnetic, charged and neutral particles. The media can be gases, liquids, solids and soft matter. Depending on the combination of radiation and material different dosimetry techniques may be proposed based on different physical interactions. Some of them are already well established in the clinical environment such as ionometry, optical densitometry with radiological films, thermoluminescence, semiconductor devices and others are beginning to gain increasing importance as optically stimulated luminescence, radiochromic films, radiophotoluminescence, with commercial products available. However, there is a plethora of other techniques available that may have specific applications and significant developments in recent years that may make them accessible at the clinical settings. A review of the state of the art of some of these still exotic techniques will be carried out showing its potentialities and applications. 101 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Pulse-by-pulse dosimetry of IMRT with a diamond-based CVD detector RP Hugtenburg1, MAM Hanifa1, RF Page2, JJ Velthuis2 1 2 Swansea University, UK. University of Bristol, UK. Abstract Intensity modulated radiotherapy brings new challenges to dosimetry, including correcting for the effects of small radiation fields and varying dose-rates on dosimeters. Recently artificial diamonds from chemical vapour deposition (CVD) process have been shown to achieve high orders of dosimetric precision, however non-linearities in dose-rate response create complexities for emergent modalities with large variations in dose-rate, such as volumetric modulated arc therapy (VMAT) and flattening-filter free systems. An electrometer has been designed to operate at MHz resolution, in order to resolve individual LINAC pulses, whilst recording dose. In this configuration we observe high orders of linearity, suggesting that non-linear effects observed in other studies may not simply be due to recombination processes, e.g. the Fowler effect, and may be due to signal processing. We show that the ability to resolve individual pulses provides an independent measurement of the LINAC monitor unit and to distinguish between average and instantaneous dose-rate effects. 102 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Experiencia cubana sobre el uso de la terapia electroquímica en cáncer Luis Berges Universidad de Oriente, Santiago de Cuba, Cuba Resumen La terapia electroquímica se usa para el tratamiento de tumores malignos y benignos. La misma es segura, simple, induce efectos adversos mínimos en el organismo, efectiva, de bajo costo y se puede aplicar cuando la terapias convencionales (cirugía, radioterapia, quimioterapia e inmunoterapia) fracasan o no pueden aplicarse. El objetivo es mostrar las experiencias cubana e internacional sobre los efectos que induce esta terapia en el tumor y en el organismo. Se muestran los principales resultados de los estudios in vitro, preclínicos y clínicos. Además, se exponen los mecanismos de acción antitumoral de la terapia electroquímica y las problemáticas existentes que conllevan al uso de las modelaciones matemáticas. Por otra parte, se exponen los principales resultados que se obtienen de la aplicación e interpretación de esta terapia en la cinética de crecimiento de tumores. 103 ISSSD 2017 Book of abstracts ISSSD 2017 September 26 to 30th, 2017. Santo Domingo, Dominican Republic. Sociedad Mexicana de Irradiación y Dosimetría Universidad Autónoma de Santo Domingo Santo Domingo, Dominican Republic 2017 104 ISSSD 2017 Book of abstracts