Journal of Applied Clinical Medical Physics, Oct 29, 2017
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Medical Physics 3.0 (MP3.0) advocates that the roles of medical physics need to be redefined and ... more Medical Physics 3.0 (MP3.0) advocates that the roles of medical physics need to be redefined and reinvigorated, and furthering leadership roles was identified as a key focus. Inevitably, most medical physicists are called upon to be actively involved in major decision making at their place(s) of business, and this includes managing human resources, administrative oversight, consulting, budgeting, grand capital purchasing, and strategic planning, all of which are duties that require a wide array of leadership qualities. In an effort to address the need to improve leadership in the medical physics profession, the AAPM Summer School in 2016 provided a focused and hands-on environment for medical physicists who had interests in developing their leadership and management skills. As an outgrowth of these activities, the AAPM has formed a Leadership Academy Working Group on providing resources and course training for medical physicists to further improve those skills. These approaches This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
We have determined the optimal method for modeling kyphoplasty cement to enable accurate dose cal... more We have determined the optimal method for modeling kyphoplasty cement to enable accurate dose calculations in the Eclipse treatment planning system (TPS). The cement studied (Medtronic Kyphon HV‐R®) consists of 30% Barium, 68% polymethylmethacrylate (PMMA), and 2% benzoyl peroxide, formulated to be radiopaque with kV imaging systems. Neither Barium nor PMMA have a high physical density, resulting in different interaction characteristics for megavoltage treatment beams compared to kV imaging systems. This can lead to significant calculation errors if density mapping is performed using a standard CT number to density curve. To properly characterize the cement for dose calculation, we 3D printed a hemi‐cylindrical container to fit adjacent to a micro‐chamber insert for an anthropomorphic phantom, and filled the container with Kyphon cement. We CT scanned the combination, modeled the cement with multiple material assignments in the TPS, designed plans with different field sizes and beam...
Preamble The American Association of Physicists in Medicine (AAPM) is a nonprofit professional so... more Preamble The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and e...
Vendor‐provided commercialized equipment and software are well accepted in the medical physics pr... more Vendor‐provided commercialized equipment and software are well accepted in the medical physics profession, since they are designed to free up physicists’ time, improve workflow efficiency, and provide higher accuracy and precision. There have been clear lines dividing three parties, at least in the field of radiation oncology: patients, health care providers, and medical device suppliers. Medical physicists (and dosimetrists) are part of the health care providers group. One of their main duties, as defined by IAEA (International Atomic Energy Agency), is “mainly related to the safety and performance of related equipment and computer systems”. Therefore, any financial relationship between medical physicists and medical device vendors should be clearly disclosed to avoid conflicts of interest (COI). However, in recent years, vendors of radiotherapy equipment and software are increasingly engaged in directly providing radiotherapy physics services to the clinic. This includes not only ...
In an era of automated measurements and analysis, the time and resource intensive process of dosi... more In an era of automated measurements and analysis, the time and resource intensive process of dosimetric plan verification for Intensity Modulated Radiation Therapy treatments would seem to be ripe for improvement. In this Point-Counterpoint contribution the authors debate benefits of methods both hypothetical and established. I offer thanks to our contributors and note that they are writing in the classic style of a debate, the opinions that they argue may or may not reflect their personal views."
ABSTRACT Medical physics is experiencing profound changes, including some with an unpredictable i... more ABSTRACT Medical physics is experiencing profound changes, including some with an unpredictable impact on the professional, educational, and scientific aspects of the profession. Impending requirements for professional certification, increased sub‐specialization, and greater emphasis on the monetary benefits of a clinical career are among the changes that place future medical physics research in jeopardy, with a potential diminution in the innovation and creativity that have been the hallmark of progress leading to improvements in patient care over the past 50 years. The President's Symposium focuses on the research challenges and opportunities confronting the medical physics profession. A historical review shows how research has been a key factor in the evolution, expansion, and enhanced stature of medical physics in health care delivery. For young investigators contemplating a research career, challenges include the increasingly competitive environment for research funding, difficulties in balancing research versus clinical training in order to be eligible for professional certification, the lure of more stable employment with higher remuneration in the clinical setting, and an uncertain market for medical physicists desiring research careers. Research opportunities in medical physics are presented as a desirable component of medical physicseducational programs. The balance of research, didactic education and clinical training in a medical physicist's education needs careful delineation. The assimilation of Ph.D. graduate and post‐doctoral students into educational programs and the practice of medical physics are explored in terms of possible pathways, such as combined clinical and research degree programs and residencies. Finally, the challenge of sustaining research amidst the challenges of clinical and professional duties is discussed. Brief presentations by the speakers will be followed by audience discussion.
Radiotherapy (RT) treatment is a complex process that requires the entire radiation oncology team... more Radiotherapy (RT) treatment is a complex process that requires the entire radiation oncology team working together to ensure a safe, expeditious, and effective treatment of patients in the clinic. Standardizing the RT workflow is considered essential to improve RT treatment quality and reduce miscommunication or human errors.
The aim of this guideline is to present recommendations regarding moderately hypofractionated (24... more The aim of this guideline is to present recommendations regarding moderately hypofractionated (240-340 cGy per fraction) and ultrahypofractionated (500 cGy or more per fraction) radiation therapy for localized prostate cancer. The American Society for Radiation Oncology convened a task force to address 8 key questions on appropriate indications and dose-fractionation for moderately and ultrahypofractionated radiation therapy, as well as technical issues, including normal tissue dose constraints, treatment volumes, and use of image guided and intensity modulated radiation therapy. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and Society-approved tools for grading evidence quality and recommendation strength. Based on high-quality evidence, strong consensus was reached for offering moderate hypofractionation across risk groups to patients choosing external beam radiation therapy. The task force conditionally recommends ultrahypofractionated radiation may be offered for low- and intermediate-risk prostate cancer but strongly encourages treatment of intermediate-risk patients on a clinical trial or multi-institutional registry. For high-risk patients, the task force conditionally recommends against routine use of ultrahypofractionated external beam radiation therapy. With any hypofractionated approach, the task force strongly recommends image guided radiation therapy and avoidance of nonmodulated 3-dimensional conformal techniques. Hypofractionated radiation therapy provides important potential advantages in cost and convenience for patients, and these recommendations are intended to provide guidance on moderate hypofractionation and ultrahypofractionation for localized prostate cancer. The limits in the current evidentiary base-especially for ultrahypofractionation-highlight the imperative to support large-scale randomized clinical trials and underscore the importance of shared decision making between clinicians and patients.
Journal of applied clinical medical physics, Jan 8, 2017
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society who... more The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnos...
ABSTRACT Purpose: Treatment couch tops in medical LINAC rooms lead to attenuation to beams penetr... more ABSTRACT Purpose: Treatment couch tops in medical LINAC rooms lead to attenuation to beams penetrating them, plus higher skin dose which can become a significant concern with the high fraction doses associated with Stereotactic Body Radiation Therapy. This work measures the attenuation and shallow depth dose due to a BrainLab couch, and studies the modeling of the couch top in our treatment planning system (TPS) as a uniform solid material with homogeneous density.
cylindrical phantom containing a C-shape target that encloses a sensitive structure. We used the ... more cylindrical phantom containing a C-shape target that encloses a sensitive structure. We used the above method to optimize the beam intensity and beam orientation simultaneously, and produced the result consistent with that generated by brute-force calculation. For a patient with nasopharyngeal cancer, the IMRT treatment plans generated with the optimized five beam angles showed significant improvements over the use of five equi-spaced intensity modulated beams. Conclusion: An algorithm based on Approximation Theory is developed to simultaneously optimize both beam intensity and beam orientation in IMRT applications. In general, this algorithm offers the following advantages: 1) guarantees a global minimum; 2) includes the non-negativity of beam weight a priori; and 3) provides a vast improvement in efficiency over conventional techniques such as simulated annealing and conjugate gradient methods. The algorithm has been applied to several problems and the results show that it has the potential for IMRT applications.
Journal of applied clinical medical physics / American College of Medical Physics, 2015
The objective for this work was to develop a commissioning methodology for the treatment delivery... more The objective for this work was to develop a commissioning methodology for the treatment delivery components of the AccuBoost system, as well as to establish a routine quality assurance program and appropriate guidance for clinical use based on the commissioning results. Various tests were developed: 1) assessment of the accuracy of the displayed separation value; 2) validation of the dwell positions within each applicator; 3) assessment of the accuracy and precision of the applicator localization system; 4) assessment of the combined dose profile of two opposed applicators to confirm that they are coaxial; 5) measurement of the absolute dose delivered with each applicator to confirm acceptable agreement with dose based on Monte Carlo modeling; 6) measurements of the skin-to-center dose ratio using optically stimulated luminescence dosimeters; and 7) assessment of the mammopad cushion's effect on the center dose. We found that the difference between the measured and the actual p...
Journal of applied clinical medical physics / American College of Medical Physics, Jan 8, 2015
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society who... more The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States.The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner.Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective us...
Journal of Applied Clinical Medical Physics, Oct 29, 2017
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Medical Physics 3.0 (MP3.0) advocates that the roles of medical physics need to be redefined and ... more Medical Physics 3.0 (MP3.0) advocates that the roles of medical physics need to be redefined and reinvigorated, and furthering leadership roles was identified as a key focus. Inevitably, most medical physicists are called upon to be actively involved in major decision making at their place(s) of business, and this includes managing human resources, administrative oversight, consulting, budgeting, grand capital purchasing, and strategic planning, all of which are duties that require a wide array of leadership qualities. In an effort to address the need to improve leadership in the medical physics profession, the AAPM Summer School in 2016 provided a focused and hands-on environment for medical physicists who had interests in developing their leadership and management skills. As an outgrowth of these activities, the AAPM has formed a Leadership Academy Working Group on providing resources and course training for medical physicists to further improve those skills. These approaches This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
We have determined the optimal method for modeling kyphoplasty cement to enable accurate dose cal... more We have determined the optimal method for modeling kyphoplasty cement to enable accurate dose calculations in the Eclipse treatment planning system (TPS). The cement studied (Medtronic Kyphon HV‐R®) consists of 30% Barium, 68% polymethylmethacrylate (PMMA), and 2% benzoyl peroxide, formulated to be radiopaque with kV imaging systems. Neither Barium nor PMMA have a high physical density, resulting in different interaction characteristics for megavoltage treatment beams compared to kV imaging systems. This can lead to significant calculation errors if density mapping is performed using a standard CT number to density curve. To properly characterize the cement for dose calculation, we 3D printed a hemi‐cylindrical container to fit adjacent to a micro‐chamber insert for an anthropomorphic phantom, and filled the container with Kyphon cement. We CT scanned the combination, modeled the cement with multiple material assignments in the TPS, designed plans with different field sizes and beam...
Preamble The American Association of Physicists in Medicine (AAPM) is a nonprofit professional so... more Preamble The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and e...
Vendor‐provided commercialized equipment and software are well accepted in the medical physics pr... more Vendor‐provided commercialized equipment and software are well accepted in the medical physics profession, since they are designed to free up physicists’ time, improve workflow efficiency, and provide higher accuracy and precision. There have been clear lines dividing three parties, at least in the field of radiation oncology: patients, health care providers, and medical device suppliers. Medical physicists (and dosimetrists) are part of the health care providers group. One of their main duties, as defined by IAEA (International Atomic Energy Agency), is “mainly related to the safety and performance of related equipment and computer systems”. Therefore, any financial relationship between medical physicists and medical device vendors should be clearly disclosed to avoid conflicts of interest (COI). However, in recent years, vendors of radiotherapy equipment and software are increasingly engaged in directly providing radiotherapy physics services to the clinic. This includes not only ...
In an era of automated measurements and analysis, the time and resource intensive process of dosi... more In an era of automated measurements and analysis, the time and resource intensive process of dosimetric plan verification for Intensity Modulated Radiation Therapy treatments would seem to be ripe for improvement. In this Point-Counterpoint contribution the authors debate benefits of methods both hypothetical and established. I offer thanks to our contributors and note that they are writing in the classic style of a debate, the opinions that they argue may or may not reflect their personal views."
ABSTRACT Medical physics is experiencing profound changes, including some with an unpredictable i... more ABSTRACT Medical physics is experiencing profound changes, including some with an unpredictable impact on the professional, educational, and scientific aspects of the profession. Impending requirements for professional certification, increased sub‐specialization, and greater emphasis on the monetary benefits of a clinical career are among the changes that place future medical physics research in jeopardy, with a potential diminution in the innovation and creativity that have been the hallmark of progress leading to improvements in patient care over the past 50 years. The President's Symposium focuses on the research challenges and opportunities confronting the medical physics profession. A historical review shows how research has been a key factor in the evolution, expansion, and enhanced stature of medical physics in health care delivery. For young investigators contemplating a research career, challenges include the increasingly competitive environment for research funding, difficulties in balancing research versus clinical training in order to be eligible for professional certification, the lure of more stable employment with higher remuneration in the clinical setting, and an uncertain market for medical physicists desiring research careers. Research opportunities in medical physics are presented as a desirable component of medical physicseducational programs. The balance of research, didactic education and clinical training in a medical physicist's education needs careful delineation. The assimilation of Ph.D. graduate and post‐doctoral students into educational programs and the practice of medical physics are explored in terms of possible pathways, such as combined clinical and research degree programs and residencies. Finally, the challenge of sustaining research amidst the challenges of clinical and professional duties is discussed. Brief presentations by the speakers will be followed by audience discussion.
Radiotherapy (RT) treatment is a complex process that requires the entire radiation oncology team... more Radiotherapy (RT) treatment is a complex process that requires the entire radiation oncology team working together to ensure a safe, expeditious, and effective treatment of patients in the clinic. Standardizing the RT workflow is considered essential to improve RT treatment quality and reduce miscommunication or human errors.
The aim of this guideline is to present recommendations regarding moderately hypofractionated (24... more The aim of this guideline is to present recommendations regarding moderately hypofractionated (240-340 cGy per fraction) and ultrahypofractionated (500 cGy or more per fraction) radiation therapy for localized prostate cancer. The American Society for Radiation Oncology convened a task force to address 8 key questions on appropriate indications and dose-fractionation for moderately and ultrahypofractionated radiation therapy, as well as technical issues, including normal tissue dose constraints, treatment volumes, and use of image guided and intensity modulated radiation therapy. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and Society-approved tools for grading evidence quality and recommendation strength. Based on high-quality evidence, strong consensus was reached for offering moderate hypofractionation across risk groups to patients choosing external beam radiation therapy. The task force conditionally recommends ultrahypofractionated radiation may be offered for low- and intermediate-risk prostate cancer but strongly encourages treatment of intermediate-risk patients on a clinical trial or multi-institutional registry. For high-risk patients, the task force conditionally recommends against routine use of ultrahypofractionated external beam radiation therapy. With any hypofractionated approach, the task force strongly recommends image guided radiation therapy and avoidance of nonmodulated 3-dimensional conformal techniques. Hypofractionated radiation therapy provides important potential advantages in cost and convenience for patients, and these recommendations are intended to provide guidance on moderate hypofractionation and ultrahypofractionation for localized prostate cancer. The limits in the current evidentiary base-especially for ultrahypofractionation-highlight the imperative to support large-scale randomized clinical trials and underscore the importance of shared decision making between clinicians and patients.
Journal of applied clinical medical physics, Jan 8, 2017
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society who... more The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnos...
ABSTRACT Purpose: Treatment couch tops in medical LINAC rooms lead to attenuation to beams penetr... more ABSTRACT Purpose: Treatment couch tops in medical LINAC rooms lead to attenuation to beams penetrating them, plus higher skin dose which can become a significant concern with the high fraction doses associated with Stereotactic Body Radiation Therapy. This work measures the attenuation and shallow depth dose due to a BrainLab couch, and studies the modeling of the couch top in our treatment planning system (TPS) as a uniform solid material with homogeneous density.
cylindrical phantom containing a C-shape target that encloses a sensitive structure. We used the ... more cylindrical phantom containing a C-shape target that encloses a sensitive structure. We used the above method to optimize the beam intensity and beam orientation simultaneously, and produced the result consistent with that generated by brute-force calculation. For a patient with nasopharyngeal cancer, the IMRT treatment plans generated with the optimized five beam angles showed significant improvements over the use of five equi-spaced intensity modulated beams. Conclusion: An algorithm based on Approximation Theory is developed to simultaneously optimize both beam intensity and beam orientation in IMRT applications. In general, this algorithm offers the following advantages: 1) guarantees a global minimum; 2) includes the non-negativity of beam weight a priori; and 3) provides a vast improvement in efficiency over conventional techniques such as simulated annealing and conjugate gradient methods. The algorithm has been applied to several problems and the results show that it has the potential for IMRT applications.
Journal of applied clinical medical physics / American College of Medical Physics, 2015
The objective for this work was to develop a commissioning methodology for the treatment delivery... more The objective for this work was to develop a commissioning methodology for the treatment delivery components of the AccuBoost system, as well as to establish a routine quality assurance program and appropriate guidance for clinical use based on the commissioning results. Various tests were developed: 1) assessment of the accuracy of the displayed separation value; 2) validation of the dwell positions within each applicator; 3) assessment of the accuracy and precision of the applicator localization system; 4) assessment of the combined dose profile of two opposed applicators to confirm that they are coaxial; 5) measurement of the absolute dose delivered with each applicator to confirm acceptable agreement with dose based on Monte Carlo modeling; 6) measurements of the skin-to-center dose ratio using optically stimulated luminescence dosimeters; and 7) assessment of the mammopad cushion's effect on the center dose. We found that the difference between the measured and the actual p...
Journal of applied clinical medical physics / American College of Medical Physics, Jan 8, 2015
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society who... more The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States.The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner.Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective us...
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