mimicking WT and CIP resistant J774 cells, by fluorescence polarization spectroscopy. In this res... more mimicking WT and CIP resistant J774 cells, by fluorescence polarization spectroscopy. In this respect, we observed a decrease in the melting temperature in vesicles mimicking the membrane composition of CIP resistant cells, indicating that changes in the fluidity of these membranes may be due to the decrease of SM. Studies are currently performed to investigate potential changes in other components of rafts like glucosylceramides. These data might have important relevance to relate the interaction of fluoroquinolones with lipids and change in the processes involved in cellular accumulation of fluoroquinolones.
Journal of The National Comprehensive Cancer Network, Jul 1, 2010
Colorectal cancer is less common in the Middle East and South Asia than in western countries, wit... more Colorectal cancer is less common in the Middle East and South Asia than in western countries, with the rectum the most common primary site, unlike in the United States. A project was planned to address various local issues regarding the management of common cancers, including colorectal cancer, and to adapt the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) to the Middle East and North Africa (MENA) region. A survey of oncologists in this geographic area showed that the management practices and issues regarding colorectal cancer are similar to those presented in the NCCN Colorectal Cancer Guidelines. However, 2 major differences exist: most oncologists in the MENA region prefer chest radiograph over CT in pretreatment workup, and almost 50% of Colorectal cancer is less common in the Middle East and South Asia region than in the United States (Table 1). However, it is among the 10 most common cancer types in all the countries. 1 The age-standardized incidence rate is below 10 per 100,000 in most countries in this region, and ranges between 10 to 40 per 100,000 in a few countries such as Turkey, Qatar, Kuwait, and Israel. 1 In a study from Turkey, one third of patients were younger than 50 years, and the rectum was the most common site of occurrence (42.5%), followed by the sigmoid colon (23.2%). 2 The epidemiologic features are similar in India. 3 However, in a study from Qatar, the descending and sigmoid colon were the most common sites. 4 Although the management of colorectal cancer should ideally be based on evidence-based medicine, standardized practices do not exist in other parts of the world. The social, cultural, and economic differences among the countries may be responsible for this lack of standard management. The paucity of local randomized trials from the
International Journal of Radiation Oncology Biology Physics, Nov 1, 2015
bi-directional product (BP), volume of the post-surgical cavity including surrounding enhancement... more bi-directional product (BP), volume of the post-surgical cavity including surrounding enhancement (Vol), and volume of T1+C enhanced rim (Rim) with the cavity subtracted. We first sought to determine if a 25% increase between PO and 1 or 3 month T1+C MRIs was predictive of worsened OS and PFS for each technique. If significant, we planned to determine if a 5% increase, or any increase were also predictive. Results: Median age was 61.8 years. Median OS and PFS were 18.6 and 11.7 months. A relative increase in Rim volume of 25% at 3 months was a poor prognostic factor for OS (15.2 vs 31.3 months pZ0.001) and for PFS (10.0 vs 15.5 months pZ0.011). Even at 1 month, Rim increase of 25% was a poor prognostic factor for OS and for PFS. Vol and BP change did not statistically significantly predict for OS. Rim increase of only 5% at 1 month also predicted for worse OS (15.2 vs 26.9 months pZ0.010). Further, at 1 month, any increase in Rim enhancement was associated with worse OS (15.2 vs 21.3 months pZ0.025). Conclusion: Even minor change in the relative amount of enhancement surrounding the post-surgical cavity is an early prognostic factor for OS and PFS. Changes of Vol or BP were not significant predictors of OS. These findings suggest that either a lack of early response or underappreciated progression portends a significantly worse prognosis and raises the question of whether salvage therapies should be considered earlier in these patients.
Objectives: Evaluation of treatment results of patients who received stereotactic radiosurgery an... more Objectives: Evaluation of treatment results of patients who received stereotactic radiosurgery and fractionated stereotactic radiotherapy (SRS-FSRT) for uveal melanoma. Methods: We retrospectively evaluated 163 patients who received SRS-FSRT between 2007 and 2013 with the diagnosis of uveal melanoma. Treatments were applied with CyberKnife® (Accuray Inc., Sunnyvale, CA, USA). Median age of the patients was 54 years (18-82 years). Ninety-six (59%) patients were male, and 67 (41%) patients were female. The tumor was located in the choroid in 146 patients (90%), and in the iris ciliary body in 17 patients (10%). According to the Collaborative Ocular Melanoma Study (COMS), tumor size was small in 8 (5%), medium in 49 (30%), and large in 106 (65%) patients. SRS-FSRT was applied in median 3 (1-3) fractions with a total of median 54 Gy (10-60 Gy). Median maximum GTV dose was 63 Gy.
Japanese Journal of Clinical Oncology, Jun 16, 2020
Purpose: Stereotactic body radiotherapy (SBRT) is an effective treatment option for patients with... more Purpose: Stereotactic body radiotherapy (SBRT) is an effective treatment option for patients with early-stage non-small cell lung cancer (NSCLC). In this study, we evaluated the treatment results using two different SBRT techniques and the effect of beam-on time (BOT) on treatment outcomes. Methods: Between July 2007 and January 2018, 142 patients underwent SBRT for primary NSCLC. We have delivered SBRT using either respiratory tracking system (RTS) or internal-target-volume (ITV)-based motion management techniques. The effect of age, tumor size, pretreatment tumor SUVmax value, presence of tissue diagnosis, histopathological subtype, operability status, tumor location, motion management technique, BED10 value, BOT on overall survival (OS), loco-regional control (LRC), event-free survival (EFS) and primary tumor control (PTC) were evaluated. Results: Median age of the patients was 70 years (range, 39-91 years). Most of the patients were inoperable (90%) at the time of SBRT. Median BED10 value was 112.5 Gy. With a median follow-up of 25 months, PTC was achieved in 91.5% of the patients. Two-year estimated OS, LRC, PTC and EFS rates were 68, 63, 63 and 53%, respectively. For the entire group, OS was associated with BOT (P = 0.027), and EFS was associated with BOT (P = 0.027) and tumor size (P = 0.015). For RTS group, OS was associated with age (P = 0.016), EFS with BOT (P = 0.05) and tumor size (P = 0.024), LRC with BOT (P = 0.008) and PTC with BOT (P = 0.028). The treatment was well tolerated in general. Conclusion: SBRT is an effective and safe treatment with high OS, LRC, EFS and PTC rates in patients with primary NSCLC. Protracted BOT might deteriorate SBRT outcomes.
Malignant pleural mesothelioma (MPM) due to environmental exposure to asbestos and erionite is a ... more Malignant pleural mesothelioma (MPM) due to environmental exposure to asbestos and erionite is a relatively common cancer in Turkey. In this study, we investigated the value of flow cytometric (FCM) DNA analysis and other prognostic factors such as age and etiologic factor in the patients with MPM, treated with surgery±combination chemotherapy±radiotherapy. A total of 40 patients with a median age
Purpose: To determine the safety and effectiveness of accelerated hyperfractionated radiotherapy ... more Purpose: To determine the safety and effectiveness of accelerated hyperfractionated radiotherapy in the treatment of supratentorial malignant astrocytomas.Materials and methods: Between June 1995–July 1997, 75 patients were enrolled to a prospective phase II study. A total dose of 60 Gy was delivered in 2 Gy b.i.d. fractions with an interval of 6–8 h, 5 days per week, in an overall
Vitreous humor (VH) is not considered as a critical structure in the radiotherapy planning proces... more Vitreous humor (VH) is not considered as a critical structure in the radiotherapy planning process. In the present study, an experimental animal model was performed to examine the effects of radiotherapy on VH. The right eyes of twelve New Zealand rabbits were irradiated to 60 Gy in 3 fractions in accordance with the scheme used in the treatment of uveal melanoma in our clinic, and contralateral (left) eyes were considered as control. Weekly ophthalmologic examination was performed after irradiation, for three months. At the end of the third month, enucleation and vitreous collection were conducted. The vitreous samples were subjected to metabolomic analyses, ELISA analyses, viscosity measurements, and electron microscopic examination. In control and experimental vitreous samples, 275 different metabolites were identified, and 34 were found to differ significantly between groups. In multivariate analyzes, a clear distinction was observed between control and irradiated vitreous samples. Pathway analysis revealed that nine pathways were affected, and these pathways were mainly related to amino acid metabolism. A significant decrease was observed in the expressions of type II, V, and XI collagens in protein level in the ELISA. There was a non-significant decrease in type IX collagen and viscosity. Electron microscopic examination revealed disrupted collagen fibrillar ultra-structure and dispersed collagen fragments in the experimental vitreous. An intact vitreous is essential for a healthy eye. In this study, we observed that radiation causes changes in the vitreous that may have long-term consequences.
Archives of Biochemistry and Biophysics, Apr 1, 2012
Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of... more Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH 2 groups of lipids decreased significantly and the carbonyl esters, olefinic@CH and CH 3 groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems.
Background Stereotactic body radiotherapy (SBRT) allows the delivery of an ablative radiation dos... more Background Stereotactic body radiotherapy (SBRT) allows the delivery of an ablative radiation dose to the tumor with minimal toxicity. Although magnetic resonance imaging (MRI)-guided SBRT appears to be a promising approach in the modern era, X-ray image-guided SBRT is still used worldwide for pancreatic cancer. This study aims to evaluate the results of X-ray image-guided SBRT in patients with locally advanced pancreatic cancer (LAPC). Methodology Medical records of 24 patients with unresectable LAPC who underwent X-ray image-guided SBRT between 2009 and 2022 were retrospectively evaluated. SPSS version 23.0 (IBM Corp., Armonk, NY, USA) was utilized for all analyses. Results The median age was 64 years (range = 42-81 years), and the median tumor size was 3.5 cm (range = 2.7-4 cm). The median total dose of SBRT was 35 Gy (range = 33-50 Gy) in five fractions. After SBRT, 30% of patients showed complete and 41% showed partial response, whereas 20% had stable disease and 9% had progression. Median follow-up was 15 months (range = 6-58 months). During follow-up, four (16%) patients had local recurrence, one (4%) had a regional recurrence, and 17 (70%) had distant metastasis (DM). The two-year local control (LC), local recurrence-free survival (LRFS), overall survival (OS), and DM-free survival (DMFS) rate was 87%, 36%, 37%, and 29%, respectively. In univariate analysis, a larger tumor size (>3.5 cm) and higher cancer antigen 19-9 level (>106.5 kU/L) significantly decreased the OS, LRFS, and DMFS rates. No severe acute toxicity was observed. However, two patients had severe late toxicity as intestinal bleeding. Conclusions X-ray image-guided SBRT provides a good LC rate with minimal toxicity for unresectable LAPC. However, despite modern systemic treatments, the rate of DM remains high which plays a major role in survival.
Turkish Journal of Geriatrics-Turk Geriatri Dergisi, Apr 1, 2014
Glioblastom insidans› yaflla artmaktad›r. Bu çal›flmada yafll› glioblastom tan›l› olgular›n radyo... more Glioblastom insidans› yaflla artmaktad›r. Bu çal›flmada yafll› glioblastom tan›l› olgular›n radyoterapi sonuçlar› de¤erlendirilmifltir. Gereç ve Yöntem: Haziran 2002 ve Aral›k 2011 tarihleri aras›nda tedavi uygulanan 65 yafl ve üzeri 65 olgunun verileri de¤erlendirildi. Hastalar›n ortanca yafl› 70 olup (65-84 yafl) 45'i erkektir. Karnofsky performans durumu hastalar›n %82'sinde ≥70'tir. Otuz iki hastada gros tümör rezeksiyonu yap›lm›flt›r. Radyoterapi 59 hastada lokalize alana (tümör/ tümör yata¤›), 6 hastada tüm beyin ve lokalize alana yönelik uygulanm›flt›r. Tedavi dozu medyan 60 Gy'dir (20-60 Gy). Otuz bir hasta eflzamanl›, 17 hasta adjuvan temozolomide alm›flt›r. Bulgular: Ortanca izlem süresi 5 ayd›r (1-44 ay). Bir ve iki y›ll›k genel sa¤kal›m oranlar› s›ra-s›yla %38,9 ve %11,7'dir. Tedavi alanlar›na göre bak›ld›¤›nda ortanca sa¤kal›m lokalize radyoterapi alan grupta 9 ay (7-11 ay), tüm beyin radyoterapisi alanlarda 3 ay (1-6 ay) ve tüm beyin ve lokalize alana yönelik radyoterapi alanlarda 18 ayd›r (3-18 ay) (p=0,04). Cinsiyet, performans durumu, radyoterapi dozu ve cerrahi tipi sa¤kal›m oranlar›n› anlaml› olarak etkilememifltir. Orta hat yerleflimli tümörlerde di¤er yerleflimli tümörlere göre hastal›k daha kötü seyretmektedir (p=0,01). Adjuvan temozolamide alanlarda sa¤kal›m daha iyi bulunmufltur (p=0,02). Sonuç: Glioblastom tan›l› yafll› hastalarda radyoterapi uygun bir tedavi yaklafl›m›d›r. Bu çal›flmada gruplarda hasta say›s› az olmakla birlikte tüm beyin ve lokalize radyoterapi alanlarda ve adjuvan temozolamide alan hastalarda sa¤kal›m daha iyi bulunmufltur.
Objectives: Evaluation of treatment results in patients with recurrent head and neck cancer (HNC)... more Objectives: Evaluation of treatment results in patients with recurrent head and neck cancer (HNC) treated with stereotactic radiotherapy (SRT).
International Journal of Radiation Oncology Biology Physics, Oct 1, 2016
Purpose/Objective(s): Stage III cutaneous melanoma incorporates a heterogeneous patient group wit... more Purpose/Objective(s): Stage III cutaneous melanoma incorporates a heterogeneous patient group with node-positive disease. Adjuvant radiation therapy (RT) decreases regional recurrence but its use is sporadic, in part due to a high competing risk of distant failure. This study aimed to assess our institutional practice patterns, evaluate clinical outcomes post-RT, and identify risk factors for distant metastases in stage III melanoma patients. Materials/Methods: This study received institutional ethics approval. Patients who received adjuvant RT for node-positive melanoma between 2009 and 2014 were included. Kaplan-Meier estimates of overall survival (OS) and 95% confidence intervals (CI) were obtained. Logistic regression was used to explore the association between patient, tumor, and treatment factors for the outcomes of these patients. Results: Forty-one patients were analyzed. Median follow-up was 2 years. In all, 61% presented with palpable nodal disease, and 66% had a sentinel lymph node procedure prior to completion nodal dissection. Patients had an average of 3 involved lymph nodes and 23 total lymph nodes removed. Extracapsular extension was present in 51% of patients. Sixty-one percent of patients received hypofractionated RT (30 Gy/5 fractions or 36 Gy/6 fractions over 2.5-3 weeks) versus 39% who received conventional fractionation (typically 48 Gy/20 fractions). Regional radiation targets included the axilla (39%), head and neck (32%), and groin (29%). At 2 years, regional control was 82% and distant control was 46%. Median OS was 3.7 years. All patients who experienced a regional failure post-RT developed distant metastases and died of melanoma. All patients who were free of distant failure had regional control. Development of distant metastases was strongly associated with extracapsular extension (HR 4.0, 95% CI 1.8-8.7, P<0.0001). T stage, N stage, RT dose, neurotropism, nodal size, location, and number involved were not associated with regional or distant control. Conclusion: Patients who receive adjuvant RT for node-positive melanoma have high rates of regional control but are prone to distant failure. Regional failure is a harbinger of distant disease. Extracapsular extension also predicts distant failure in this population. Future research should compare outcomes with patients that did not receive RT and investigate the role of novel systemic therapies in preventing distant metastases.
Purpose: Intracranial germ cell tumors (ICGCTs) comprise approximately 0.4%–3% of all brain tumor... more Purpose: Intracranial germ cell tumors (ICGCTs) comprise approximately 0.4%–3% of all brain tumors. In this study, we aim to evaluate clinical characteristics, treatment and outcomes of patients with ICGCT. Patients and Methods: All patients with ICGCT diagnosed in Hacettepe University's Pediatric Oncology Department between January 1980 and January 2016 were evaluated, retrospectively. Results: We identified 52 patients (male/female: 2.46) diagnosed with ICGT. Median age was 140 months. The median duration of symptoms was 3 months. Patients with endocrine symptoms were diagnosed later than others (P = 0.028). The primary site was pineal region in 20 patients, nonpineal region in 32 which included six bifocal involvements. Pineal location was more common in boys than girls (P = 0.02). Histopathological diagnosis was germinoma in 28 patients, nongerminomatous malignant germ cell tumors in 14 and immature teratoma in 4. The mean age for germinoma was higher than that of nongerminomatous tumors (P = 0.032). Patients treated with surgery and radiotherapy and chemotherapy. Median follow-up time was 52.5 months. Thirty-six patients were alive for 12–228 months. Relapsed/progressive disease was observed in 11 patients. Nongerminomatous tumors more frequently showed relapse/progression than germinoma (P = 0.06). Five-year overall and event-free survival rates for the whole group were 72.6% and 57.2%, respectively. Overall and event-free survival rates for germinoma were better than malignant nongerminomatous tumors. Conclusion: Although the ratio of ICGCTs to central nervous system tumors in our series was similar to western countries, some clinical features such as tumor location were similar to cases from East Asian countries. Although similar protocols were used survival rates lower than developed western and eastern developed countries.
Purpose.-To evaluate the efficacy and toxicity of hypofractionated radiotherapy in non-metastatic... more Purpose.-To evaluate the efficacy and toxicity of hypofractionated radiotherapy in non-metastatic soft tissue and bone sarcomas. Patients and methods.-Thirty patients underwent hypofractionated radiotherapy between 2007 and 2015. Overall, 17 patients underwent primary hypofractionated radiotherapy, nine underwent hypofractionated radiotherapy for reirradiation, and four received a boost dose via hypofractionated radiotherapy after external beam radiotherapy. Most common disease sites were head and neck and retroperitoneum. Hypofractionated radiotherapy was administered with a definitive, adjuvant, or neoadjuvant intent. Results.-Median age was 37 years (range: 11-82 years). Median hypofractionated radiotherapy dose was 35 Gy (range: 20-50 Gy) in three to five fractions. Median follow-up was 21 months (range: 1-108 months). One-and 2-year overall survival rate was 75% and 52%, respectively. One-and 2-year local recurrence-free survival rate was 59% and 48%, with local recurrence rates of 16% and 33% in 1 and 2 years, respectively. Univariate analysis revealed tumour size (P = 0.04), hypofractionated radiotherapy intent (P = 0.016) and reirradiation (P = 0.001) as prognostic factors for local recurrence-free survival. Severe late toxicity was observed in one patient as grade 3 trismus. Conclusion.-Hypofractionated radiotherapy as the primary treatment or for reirradiation has been shown to be safe in the treatment of bone and soft tissue sarcomas. It can provide relatively good local control and survival rates.
This study aims to dosimetrically compare multi-leaf collimator (MLC)-based and cone-based 3D LAT... more This study aims to dosimetrically compare multi-leaf collimator (MLC)-based and cone-based 3D LATTICE radiotherapy (LRT) plans. Valley-peak ratios were evaluated using seven different 3D LATTICE designs. Target volumes of 8 cm and 12 cm were defined on the RANDO phantom. Valley-peak dose patterns were obtained by creating high-dose vertices in the target volumes. By changing the vertex diameter, vertices separation, and volume ratio, seven different LATTICE designs were generated. Treatment plans were implemented using CyberKnife and Varian RapidArc. Thermoluminescent dosimeter (TLD), EBT3 films, and electronic portal-imaging device (EPID) were employed for dosimetric treatment verification, and measured doses were compared to calculated doses. By changing the vertex diameter and vertices separation, the valley-peak ratio was exhibited little difference between the two systems. By changing the vertex diameter and volume ratio, the valley-peak ratio was observed nearly the same for t...
mimicking WT and CIP resistant J774 cells, by fluorescence polarization spectroscopy. In this res... more mimicking WT and CIP resistant J774 cells, by fluorescence polarization spectroscopy. In this respect, we observed a decrease in the melting temperature in vesicles mimicking the membrane composition of CIP resistant cells, indicating that changes in the fluidity of these membranes may be due to the decrease of SM. Studies are currently performed to investigate potential changes in other components of rafts like glucosylceramides. These data might have important relevance to relate the interaction of fluoroquinolones with lipids and change in the processes involved in cellular accumulation of fluoroquinolones.
Journal of The National Comprehensive Cancer Network, Jul 1, 2010
Colorectal cancer is less common in the Middle East and South Asia than in western countries, wit... more Colorectal cancer is less common in the Middle East and South Asia than in western countries, with the rectum the most common primary site, unlike in the United States. A project was planned to address various local issues regarding the management of common cancers, including colorectal cancer, and to adapt the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) to the Middle East and North Africa (MENA) region. A survey of oncologists in this geographic area showed that the management practices and issues regarding colorectal cancer are similar to those presented in the NCCN Colorectal Cancer Guidelines. However, 2 major differences exist: most oncologists in the MENA region prefer chest radiograph over CT in pretreatment workup, and almost 50% of Colorectal cancer is less common in the Middle East and South Asia region than in the United States (Table 1). However, it is among the 10 most common cancer types in all the countries. 1 The age-standardized incidence rate is below 10 per 100,000 in most countries in this region, and ranges between 10 to 40 per 100,000 in a few countries such as Turkey, Qatar, Kuwait, and Israel. 1 In a study from Turkey, one third of patients were younger than 50 years, and the rectum was the most common site of occurrence (42.5%), followed by the sigmoid colon (23.2%). 2 The epidemiologic features are similar in India. 3 However, in a study from Qatar, the descending and sigmoid colon were the most common sites. 4 Although the management of colorectal cancer should ideally be based on evidence-based medicine, standardized practices do not exist in other parts of the world. The social, cultural, and economic differences among the countries may be responsible for this lack of standard management. The paucity of local randomized trials from the
International Journal of Radiation Oncology Biology Physics, Nov 1, 2015
bi-directional product (BP), volume of the post-surgical cavity including surrounding enhancement... more bi-directional product (BP), volume of the post-surgical cavity including surrounding enhancement (Vol), and volume of T1+C enhanced rim (Rim) with the cavity subtracted. We first sought to determine if a 25% increase between PO and 1 or 3 month T1+C MRIs was predictive of worsened OS and PFS for each technique. If significant, we planned to determine if a 5% increase, or any increase were also predictive. Results: Median age was 61.8 years. Median OS and PFS were 18.6 and 11.7 months. A relative increase in Rim volume of 25% at 3 months was a poor prognostic factor for OS (15.2 vs 31.3 months pZ0.001) and for PFS (10.0 vs 15.5 months pZ0.011). Even at 1 month, Rim increase of 25% was a poor prognostic factor for OS and for PFS. Vol and BP change did not statistically significantly predict for OS. Rim increase of only 5% at 1 month also predicted for worse OS (15.2 vs 26.9 months pZ0.010). Further, at 1 month, any increase in Rim enhancement was associated with worse OS (15.2 vs 21.3 months pZ0.025). Conclusion: Even minor change in the relative amount of enhancement surrounding the post-surgical cavity is an early prognostic factor for OS and PFS. Changes of Vol or BP were not significant predictors of OS. These findings suggest that either a lack of early response or underappreciated progression portends a significantly worse prognosis and raises the question of whether salvage therapies should be considered earlier in these patients.
Objectives: Evaluation of treatment results of patients who received stereotactic radiosurgery an... more Objectives: Evaluation of treatment results of patients who received stereotactic radiosurgery and fractionated stereotactic radiotherapy (SRS-FSRT) for uveal melanoma. Methods: We retrospectively evaluated 163 patients who received SRS-FSRT between 2007 and 2013 with the diagnosis of uveal melanoma. Treatments were applied with CyberKnife® (Accuray Inc., Sunnyvale, CA, USA). Median age of the patients was 54 years (18-82 years). Ninety-six (59%) patients were male, and 67 (41%) patients were female. The tumor was located in the choroid in 146 patients (90%), and in the iris ciliary body in 17 patients (10%). According to the Collaborative Ocular Melanoma Study (COMS), tumor size was small in 8 (5%), medium in 49 (30%), and large in 106 (65%) patients. SRS-FSRT was applied in median 3 (1-3) fractions with a total of median 54 Gy (10-60 Gy). Median maximum GTV dose was 63 Gy.
Japanese Journal of Clinical Oncology, Jun 16, 2020
Purpose: Stereotactic body radiotherapy (SBRT) is an effective treatment option for patients with... more Purpose: Stereotactic body radiotherapy (SBRT) is an effective treatment option for patients with early-stage non-small cell lung cancer (NSCLC). In this study, we evaluated the treatment results using two different SBRT techniques and the effect of beam-on time (BOT) on treatment outcomes. Methods: Between July 2007 and January 2018, 142 patients underwent SBRT for primary NSCLC. We have delivered SBRT using either respiratory tracking system (RTS) or internal-target-volume (ITV)-based motion management techniques. The effect of age, tumor size, pretreatment tumor SUVmax value, presence of tissue diagnosis, histopathological subtype, operability status, tumor location, motion management technique, BED10 value, BOT on overall survival (OS), loco-regional control (LRC), event-free survival (EFS) and primary tumor control (PTC) were evaluated. Results: Median age of the patients was 70 years (range, 39-91 years). Most of the patients were inoperable (90%) at the time of SBRT. Median BED10 value was 112.5 Gy. With a median follow-up of 25 months, PTC was achieved in 91.5% of the patients. Two-year estimated OS, LRC, PTC and EFS rates were 68, 63, 63 and 53%, respectively. For the entire group, OS was associated with BOT (P = 0.027), and EFS was associated with BOT (P = 0.027) and tumor size (P = 0.015). For RTS group, OS was associated with age (P = 0.016), EFS with BOT (P = 0.05) and tumor size (P = 0.024), LRC with BOT (P = 0.008) and PTC with BOT (P = 0.028). The treatment was well tolerated in general. Conclusion: SBRT is an effective and safe treatment with high OS, LRC, EFS and PTC rates in patients with primary NSCLC. Protracted BOT might deteriorate SBRT outcomes.
Malignant pleural mesothelioma (MPM) due to environmental exposure to asbestos and erionite is a ... more Malignant pleural mesothelioma (MPM) due to environmental exposure to asbestos and erionite is a relatively common cancer in Turkey. In this study, we investigated the value of flow cytometric (FCM) DNA analysis and other prognostic factors such as age and etiologic factor in the patients with MPM, treated with surgery±combination chemotherapy±radiotherapy. A total of 40 patients with a median age
Purpose: To determine the safety and effectiveness of accelerated hyperfractionated radiotherapy ... more Purpose: To determine the safety and effectiveness of accelerated hyperfractionated radiotherapy in the treatment of supratentorial malignant astrocytomas.Materials and methods: Between June 1995–July 1997, 75 patients were enrolled to a prospective phase II study. A total dose of 60 Gy was delivered in 2 Gy b.i.d. fractions with an interval of 6–8 h, 5 days per week, in an overall
Vitreous humor (VH) is not considered as a critical structure in the radiotherapy planning proces... more Vitreous humor (VH) is not considered as a critical structure in the radiotherapy planning process. In the present study, an experimental animal model was performed to examine the effects of radiotherapy on VH. The right eyes of twelve New Zealand rabbits were irradiated to 60 Gy in 3 fractions in accordance with the scheme used in the treatment of uveal melanoma in our clinic, and contralateral (left) eyes were considered as control. Weekly ophthalmologic examination was performed after irradiation, for three months. At the end of the third month, enucleation and vitreous collection were conducted. The vitreous samples were subjected to metabolomic analyses, ELISA analyses, viscosity measurements, and electron microscopic examination. In control and experimental vitreous samples, 275 different metabolites were identified, and 34 were found to differ significantly between groups. In multivariate analyzes, a clear distinction was observed between control and irradiated vitreous samples. Pathway analysis revealed that nine pathways were affected, and these pathways were mainly related to amino acid metabolism. A significant decrease was observed in the expressions of type II, V, and XI collagens in protein level in the ELISA. There was a non-significant decrease in type IX collagen and viscosity. Electron microscopic examination revealed disrupted collagen fibrillar ultra-structure and dispersed collagen fragments in the experimental vitreous. An intact vitreous is essential for a healthy eye. In this study, we observed that radiation causes changes in the vitreous that may have long-term consequences.
Archives of Biochemistry and Biophysics, Apr 1, 2012
Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of... more Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH 2 groups of lipids decreased significantly and the carbonyl esters, olefinic@CH and CH 3 groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems.
Background Stereotactic body radiotherapy (SBRT) allows the delivery of an ablative radiation dos... more Background Stereotactic body radiotherapy (SBRT) allows the delivery of an ablative radiation dose to the tumor with minimal toxicity. Although magnetic resonance imaging (MRI)-guided SBRT appears to be a promising approach in the modern era, X-ray image-guided SBRT is still used worldwide for pancreatic cancer. This study aims to evaluate the results of X-ray image-guided SBRT in patients with locally advanced pancreatic cancer (LAPC). Methodology Medical records of 24 patients with unresectable LAPC who underwent X-ray image-guided SBRT between 2009 and 2022 were retrospectively evaluated. SPSS version 23.0 (IBM Corp., Armonk, NY, USA) was utilized for all analyses. Results The median age was 64 years (range = 42-81 years), and the median tumor size was 3.5 cm (range = 2.7-4 cm). The median total dose of SBRT was 35 Gy (range = 33-50 Gy) in five fractions. After SBRT, 30% of patients showed complete and 41% showed partial response, whereas 20% had stable disease and 9% had progression. Median follow-up was 15 months (range = 6-58 months). During follow-up, four (16%) patients had local recurrence, one (4%) had a regional recurrence, and 17 (70%) had distant metastasis (DM). The two-year local control (LC), local recurrence-free survival (LRFS), overall survival (OS), and DM-free survival (DMFS) rate was 87%, 36%, 37%, and 29%, respectively. In univariate analysis, a larger tumor size (>3.5 cm) and higher cancer antigen 19-9 level (>106.5 kU/L) significantly decreased the OS, LRFS, and DMFS rates. No severe acute toxicity was observed. However, two patients had severe late toxicity as intestinal bleeding. Conclusions X-ray image-guided SBRT provides a good LC rate with minimal toxicity for unresectable LAPC. However, despite modern systemic treatments, the rate of DM remains high which plays a major role in survival.
Turkish Journal of Geriatrics-Turk Geriatri Dergisi, Apr 1, 2014
Glioblastom insidans› yaflla artmaktad›r. Bu çal›flmada yafll› glioblastom tan›l› olgular›n radyo... more Glioblastom insidans› yaflla artmaktad›r. Bu çal›flmada yafll› glioblastom tan›l› olgular›n radyoterapi sonuçlar› de¤erlendirilmifltir. Gereç ve Yöntem: Haziran 2002 ve Aral›k 2011 tarihleri aras›nda tedavi uygulanan 65 yafl ve üzeri 65 olgunun verileri de¤erlendirildi. Hastalar›n ortanca yafl› 70 olup (65-84 yafl) 45'i erkektir. Karnofsky performans durumu hastalar›n %82'sinde ≥70'tir. Otuz iki hastada gros tümör rezeksiyonu yap›lm›flt›r. Radyoterapi 59 hastada lokalize alana (tümör/ tümör yata¤›), 6 hastada tüm beyin ve lokalize alana yönelik uygulanm›flt›r. Tedavi dozu medyan 60 Gy'dir (20-60 Gy). Otuz bir hasta eflzamanl›, 17 hasta adjuvan temozolomide alm›flt›r. Bulgular: Ortanca izlem süresi 5 ayd›r (1-44 ay). Bir ve iki y›ll›k genel sa¤kal›m oranlar› s›ra-s›yla %38,9 ve %11,7'dir. Tedavi alanlar›na göre bak›ld›¤›nda ortanca sa¤kal›m lokalize radyoterapi alan grupta 9 ay (7-11 ay), tüm beyin radyoterapisi alanlarda 3 ay (1-6 ay) ve tüm beyin ve lokalize alana yönelik radyoterapi alanlarda 18 ayd›r (3-18 ay) (p=0,04). Cinsiyet, performans durumu, radyoterapi dozu ve cerrahi tipi sa¤kal›m oranlar›n› anlaml› olarak etkilememifltir. Orta hat yerleflimli tümörlerde di¤er yerleflimli tümörlere göre hastal›k daha kötü seyretmektedir (p=0,01). Adjuvan temozolamide alanlarda sa¤kal›m daha iyi bulunmufltur (p=0,02). Sonuç: Glioblastom tan›l› yafll› hastalarda radyoterapi uygun bir tedavi yaklafl›m›d›r. Bu çal›flmada gruplarda hasta say›s› az olmakla birlikte tüm beyin ve lokalize radyoterapi alanlarda ve adjuvan temozolamide alan hastalarda sa¤kal›m daha iyi bulunmufltur.
Objectives: Evaluation of treatment results in patients with recurrent head and neck cancer (HNC)... more Objectives: Evaluation of treatment results in patients with recurrent head and neck cancer (HNC) treated with stereotactic radiotherapy (SRT).
International Journal of Radiation Oncology Biology Physics, Oct 1, 2016
Purpose/Objective(s): Stage III cutaneous melanoma incorporates a heterogeneous patient group wit... more Purpose/Objective(s): Stage III cutaneous melanoma incorporates a heterogeneous patient group with node-positive disease. Adjuvant radiation therapy (RT) decreases regional recurrence but its use is sporadic, in part due to a high competing risk of distant failure. This study aimed to assess our institutional practice patterns, evaluate clinical outcomes post-RT, and identify risk factors for distant metastases in stage III melanoma patients. Materials/Methods: This study received institutional ethics approval. Patients who received adjuvant RT for node-positive melanoma between 2009 and 2014 were included. Kaplan-Meier estimates of overall survival (OS) and 95% confidence intervals (CI) were obtained. Logistic regression was used to explore the association between patient, tumor, and treatment factors for the outcomes of these patients. Results: Forty-one patients were analyzed. Median follow-up was 2 years. In all, 61% presented with palpable nodal disease, and 66% had a sentinel lymph node procedure prior to completion nodal dissection. Patients had an average of 3 involved lymph nodes and 23 total lymph nodes removed. Extracapsular extension was present in 51% of patients. Sixty-one percent of patients received hypofractionated RT (30 Gy/5 fractions or 36 Gy/6 fractions over 2.5-3 weeks) versus 39% who received conventional fractionation (typically 48 Gy/20 fractions). Regional radiation targets included the axilla (39%), head and neck (32%), and groin (29%). At 2 years, regional control was 82% and distant control was 46%. Median OS was 3.7 years. All patients who experienced a regional failure post-RT developed distant metastases and died of melanoma. All patients who were free of distant failure had regional control. Development of distant metastases was strongly associated with extracapsular extension (HR 4.0, 95% CI 1.8-8.7, P<0.0001). T stage, N stage, RT dose, neurotropism, nodal size, location, and number involved were not associated with regional or distant control. Conclusion: Patients who receive adjuvant RT for node-positive melanoma have high rates of regional control but are prone to distant failure. Regional failure is a harbinger of distant disease. Extracapsular extension also predicts distant failure in this population. Future research should compare outcomes with patients that did not receive RT and investigate the role of novel systemic therapies in preventing distant metastases.
Purpose: Intracranial germ cell tumors (ICGCTs) comprise approximately 0.4%–3% of all brain tumor... more Purpose: Intracranial germ cell tumors (ICGCTs) comprise approximately 0.4%–3% of all brain tumors. In this study, we aim to evaluate clinical characteristics, treatment and outcomes of patients with ICGCT. Patients and Methods: All patients with ICGCT diagnosed in Hacettepe University's Pediatric Oncology Department between January 1980 and January 2016 were evaluated, retrospectively. Results: We identified 52 patients (male/female: 2.46) diagnosed with ICGT. Median age was 140 months. The median duration of symptoms was 3 months. Patients with endocrine symptoms were diagnosed later than others (P = 0.028). The primary site was pineal region in 20 patients, nonpineal region in 32 which included six bifocal involvements. Pineal location was more common in boys than girls (P = 0.02). Histopathological diagnosis was germinoma in 28 patients, nongerminomatous malignant germ cell tumors in 14 and immature teratoma in 4. The mean age for germinoma was higher than that of nongerminomatous tumors (P = 0.032). Patients treated with surgery and radiotherapy and chemotherapy. Median follow-up time was 52.5 months. Thirty-six patients were alive for 12–228 months. Relapsed/progressive disease was observed in 11 patients. Nongerminomatous tumors more frequently showed relapse/progression than germinoma (P = 0.06). Five-year overall and event-free survival rates for the whole group were 72.6% and 57.2%, respectively. Overall and event-free survival rates for germinoma were better than malignant nongerminomatous tumors. Conclusion: Although the ratio of ICGCTs to central nervous system tumors in our series was similar to western countries, some clinical features such as tumor location were similar to cases from East Asian countries. Although similar protocols were used survival rates lower than developed western and eastern developed countries.
Purpose.-To evaluate the efficacy and toxicity of hypofractionated radiotherapy in non-metastatic... more Purpose.-To evaluate the efficacy and toxicity of hypofractionated radiotherapy in non-metastatic soft tissue and bone sarcomas. Patients and methods.-Thirty patients underwent hypofractionated radiotherapy between 2007 and 2015. Overall, 17 patients underwent primary hypofractionated radiotherapy, nine underwent hypofractionated radiotherapy for reirradiation, and four received a boost dose via hypofractionated radiotherapy after external beam radiotherapy. Most common disease sites were head and neck and retroperitoneum. Hypofractionated radiotherapy was administered with a definitive, adjuvant, or neoadjuvant intent. Results.-Median age was 37 years (range: 11-82 years). Median hypofractionated radiotherapy dose was 35 Gy (range: 20-50 Gy) in three to five fractions. Median follow-up was 21 months (range: 1-108 months). One-and 2-year overall survival rate was 75% and 52%, respectively. One-and 2-year local recurrence-free survival rate was 59% and 48%, with local recurrence rates of 16% and 33% in 1 and 2 years, respectively. Univariate analysis revealed tumour size (P = 0.04), hypofractionated radiotherapy intent (P = 0.016) and reirradiation (P = 0.001) as prognostic factors for local recurrence-free survival. Severe late toxicity was observed in one patient as grade 3 trismus. Conclusion.-Hypofractionated radiotherapy as the primary treatment or for reirradiation has been shown to be safe in the treatment of bone and soft tissue sarcomas. It can provide relatively good local control and survival rates.
This study aims to dosimetrically compare multi-leaf collimator (MLC)-based and cone-based 3D LAT... more This study aims to dosimetrically compare multi-leaf collimator (MLC)-based and cone-based 3D LATTICE radiotherapy (LRT) plans. Valley-peak ratios were evaluated using seven different 3D LATTICE designs. Target volumes of 8 cm and 12 cm were defined on the RANDO phantom. Valley-peak dose patterns were obtained by creating high-dose vertices in the target volumes. By changing the vertex diameter, vertices separation, and volume ratio, seven different LATTICE designs were generated. Treatment plans were implemented using CyberKnife and Varian RapidArc. Thermoluminescent dosimeter (TLD), EBT3 films, and electronic portal-imaging device (EPID) were employed for dosimetric treatment verification, and measured doses were compared to calculated doses. By changing the vertex diameter and vertices separation, the valley-peak ratio was exhibited little difference between the two systems. By changing the vertex diameter and volume ratio, the valley-peak ratio was observed nearly the same for t...
Uploads
Papers by Faruk Zorlu