American Association Of Physicists In Medicine Research Articles

AAPM Task Group Report 267: A joint AAPM GEC-ESTRO report on biophysical models and tools for the planning and evaluation of brachytherapy.

Brachytherapy utilizes a multitude of radioactive sources and treatment techniques that often exhibit widely different spatial and temporal dose delivery patterns. Biophysical models, capable of modeling the key interacting effects of dose delivery patterns with the underlying cellular processes of the irradiated tissues, can be a potentially useful tool for elucidating the radiobiological effects of complex brachytherapy dose delivery patterns and for comparing their relative clinical effectiveness. While the biophysical models have been used largely in research settings by experts, it has also been used increasingly by clinical medical physicists over the last two decades. A good understanding of the potentials and limitations of the biophysical models and their intended use is critically important in the widespread use of these models. To facilitate meaningful and consistent use of biophysical models in brachytherapy, Task Group 267 (TG-267) was formed jointly with the American Association of Physics in Medicine (AAPM) and The Groupe Européen de Curiethérapie and the European Society for Radiotherapy & Oncology (GEC-ESTRO) to review the existing biophysical models, model parameters, and their use in selected brachytherapy modalities and to develop practice guidelines for clinical medical physicists regarding the selection, use, and interpretation of biophysical models. The report provides an overview of the clinical background and the rationale for the development of biophysical models in radiation oncology and, particularly, in brachytherapy; a summary of the results of literature review of the existing biophysical models that have been used in brachytherapy; a focused discussion of the applications of relevant biophysical models for five selected brachytherapy modalities; and the task group recommendations on the use, reporting, and implementation of biophysical models for brachytherapy treatment planning and evaluation. The report concludes with discussions on the challenges and opportunities in using biophysical models for brachytherapy and with an outlook for future developments.

Recurrent medical imaging exposures for the care of patients: one way forward.

Medical imaging is both valuable and essential in the care of patients. Much of this imaging depends on ionizing radiation with attendant responsibilities for judicious use when performing an examination. This responsibility applies in settings of both individual as well as multiple (recurrent) imaging with associated repeated radiation exposures. In addressing the roles and responsibilities of the medical communities in the paradigm of recurrent imaging, both the International Atomic Energy Agency (IAEA) and the American Association of Physicists in Medicine (AAPM) have issued position statements, each affirmed by other organizations. The apparent difference in focus and approach has resulted in a lack of clarity and continued debate. Aiming towards a coherent approach in dealing with radiation exposure in recurrent imaging, the IAEA convened a panel of experts, the purpose of which was to identify common ground and reconcile divergent perspectives. The effort has led to clarifying recommendations for radiation exposure aspects of recurrent imaging, including the relevance of patient agency and the provider-patient covenant in clinical decision-making. CLINICAL RELEVANCE STATEMENT: An increasing awareness, generating some lack of clarity and divergence in perspectives, with patients receiving relatively high radiation doses (e.g., ≥ 100mSv) from recurrent imaging warrants a multi-stakeholder accord for the benefit of patients, providers, and the imaging community. KEY POINTS: • Recurrent medical imaging can result in an accumulation of exposures which exceeds 100 milli Sieverts. • Professional organizations have different perspectives on roles and responsibilities for recurrent imaging. • An expert panel reconciles differing perspectives for addressing radiation exposure from recurrent medical imaging.

AAPM WGPE report 394: Simulated error training for the physics plan and chart review.

Simulated error training is a method to practice error detection in situations where the occurrence of error is low. Such is the case for the physics plan and chart review where a physicist may check several plans before encountering a significant problem. By simulating potentially hazardous errors, physicists can become familiar with how they manifest and learn from mistakes made during a simulated plan review. The purpose of this project was to develop a series of training datasets that allows medical physicists and trainees to practice plan and chart reviews in a way that is familiar and accessible, and to provide exposure to the various failure modes (FMs) encountered in clinical scenarios. A series of training datasets have been developed that include a variety of embedded errors based on the risk-assessment performed by American Association of Physicists in Medicine (AAPM) Task Group 275 for the physics plan and chart review. The training datasets comprise documentation, screen shots, and digital content derived from common treatment planning and radiation oncology information systems and are available via the Cloud-based platform ProKnow. Overall, 20 datasets have been created incorporating various software systems (Mosaiq, ARIA, Eclipse, RayStation, Pinnacle) and delivery techniques. A total of 110 errors representing 50 different FMs were embedded with the 20 datasets. The project was piloted at the 2021 AAPM Annual Meeting in a workshop where participants had the opportunity to review cases and answer survey questions related to errors they detected and their perception of the project's efficacy. In general, attendees detected higher-priority FMs at a higher rate, though no correlation was found between detection rate and the detectability of the FMs. Familiarity with a given system appeared to play a role in detecting errors, specifically when related to missing information at different locations within a given software system. Overall, 96% of respondents either agreed or strongly agreed that the ProKnow portal and training datasets were effective as a training tool, and 75% of respondents agreed or strongly agreed that they planned to use the tool at their local institution. The datasets and digital platform provide a standardized and accessible tool for training, performance assessment, and continuing education regarding the physics plan and chart review. Work is ongoing to expand the project to include more modalities, radiation oncology treatment planning and information systems, and FMs based on emerging techniques such as auto-contouring and auto-planning.

Automated Test for Monthly Quality Assurance of Optical Surface Imaging Dynamic Localization Accuracy.

The American Association of Physicists in Medicine (AAPM) recently published the report of Task Group (TG) 302, which provides recommendations on acceptance, commissioning, and ongoing routine quality assurance (QA) for surface-guided radiation therapy (SGRT) systems. One of the recommended monthly QA tests is a dynamic localization accuracy test. This work aimed to develop an automated procedure for monthly SGRT dynamic localization QA. An anthropomorphic head phantom was rigidly attached to the 6-dof couch of a TrueBeam linac. TrueBeam Developer Mode was used to take an MV image of the phantom at the starting position, then automatically drive the couch through a series of translations and rotations, taking an MV image after each translation. The Identify SGRT system monitored the motion of the phantom surface from the starting position. Translations assessed on MV images were compared to translations reported in trajectory log files and Identify log files. Rotations were compared between trajectory log files and Identify log files. Three experiments were conducted. None of the translations or rotations from any experiment exceeded the tolerance values for stereotactic ablative body radiation therapy (SABR) recommended by AAPM TG-142. Maximum deviations from the expected translation values from MV imaging, trajectory log files, and Identify log files were -0.94mm, -0.11mm, and -0.78mm, respectively. Maximum deviations from the expected rotation values from trajectory log files and Identify log files were 0.01 and -0.2 degrees, respectively. The proposed method is a simple automated way to complete monthly dynamic localization QA of SGRT systems.

First implementation of quality control procedures on selected X-ray machines in South of Benin

Abstract Introduction: The use of X-ray equipment for medical diagnostic radiography procedures has increased due to advances and complexity of radiological procedures. Achieving good image quality while keeping exposure of workers, public and patient exposure to an acceptable level has become a prerequisite for the radiology department in order to comply with best international practices. The aim of this study was to undertake quality control measurement of seven (7) diagnostic radiography equipment in the south of Benin, the first of its kind. Material and methods: Multifunction detector (Piranha) and beam alignment test tool were used to perform quality control tests on seven (7) X-ray units. The method used as well as the interpretation of the results was based on the American Association of Physicists in Medicine (AAPM), United States Food and Drug Administration (FDA), Healing Arts Radiation Protection (HARP), Institute of Physics and Engineering in Medicine (IPEM), International Atomic Energy Agency (IAEA) and Canadian Safety code 35 (S.C 35) recommendations. Results: The quality control results showed that all X-ray equipment investigated were within standard limits for accuracy of exposure time below 10 ms; reproducibility of kVp, exposure time and dose output; specific dose-kVp2 linearity; and specific dose-mAs linearity. Five (5) out of seven (7) diagnostic X-ray machines passed quality control tests such as X-ray beam alignment, exposure time above 10 ms and kVp accuracy. One (1) X-ray machine failed the quality control test of beam filtration at 70 kVp and above. Conclusions: The findings of this study have provided baseline data for other radiology departments to embark on similar QA/QC activities, and also explore options for optimization of patient dose. However, there is a need to extend the study to cover more diagnostic X-ray machines throughout the country. It is anticipated that this would ultimately assist in improving radiation protection and safety during medical diagnostic radiological procedures.

ACPSEM position paper: pre-treatment patient specific plan checks and quality assurance in radiation oncology.

The Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) has not previously made recommendations outlining the requirements for physics plan checks in Australia and New Zealand. A recent workforce modelling exercise, undertaken by the ACPSEM, revealed that the workload of a clinical radiation oncology medical physicist can comprise of up to 50% patient specific quality assurance activities. Therefore, in 2022 the ACPSEM Radiation Oncology Specialty Group (ROSG) set up a working group to address this issue. This position paper authored by ROSG endorses the recommendations of the American Association of Physicists in Medicine (AAPM) Task Group 218, 219 and 275 reports with some contextualisation for the Australia and New Zealand settings. A few recommendations from other sources are also endorsed to complete the position.

Women in the Medical Physics Workforce: Insights from Membership Trends of the American Association of Physicists in Medicine, 1993 to 2023

PurposeWomen remain underrepresented in medical physics in the United States, and determinants of persisting disparities remain unclear. Here, we performed a detailed investigation of American Association of Physicists in Medicine (AAPM) membership trajectories to evaluate trends in Full membership with respect to gender, age, and highest degree. MethodsMembership data, including gender, date of birth, highest degree, membership type, and years of active membership for 1993-2023 were obtained from AAPM. Group I included Full members who joined AAPM in 1993 or later. A subset of Group I including only members who joined and left AAPM since 1993 (former members, Group IF) was used to calculate age at membership cessation and duration. Results were compared by gender and highest degree. A Kaplan-Meier analysis was also used to evaluate membership “survival” by age and highest degree. ResultsComplete data were available for 6,647 current and former Full members (Group I), including 2,211 former members (Group IF). On average, women became Full members at a significantly younger age than men (34.6 vs. 37.5 years of age, p<0.001) and ended their memberships (if applicable) at a significantly younger age than men (46.1 vs. 50.1 years of age, p<0.001). The Kaplan-Meier “survival” analysis showed that for a given age, women were at a significantly greater risk of membership cessation than men, and women with master's degrees had the lowest membership survival of any gender/degree subgroup. When analyzing by membership duration, there was no difference in survival by gender alone. Still, women with PhDs were found to have the greatest membership survival among gender/degree subgroups. ConclusionBoth gender and degree type influenced AAPM membership trajectories. While we have offered a discussion of possible explanations, qualitative data collected from both continuing and departing AAPM members will be critical in the ongoing journey toward gender parity in the profession of medical physics.

A Practical Method for Slice Spacing Measurement Using the American Association of Physicists in Medicine Computed Tomography Performance Phantom

Background: The slice spacing has a crucial role in the accuracy of computed tomography (CT) images in sagittal and coronal planes. However, there is no practical method for measuring the accuracy of the slice spacing. Purpose: This study proposes a novel method to automatically measure the slice spacing using the American Association of Physicists in Medicine (AAPM) CT performance phantom. Methods: The AAPM CT performance phantom module 610-04 was used to measure slice spacing. The process of slice spacing measurement involves a pair of axial images of the module containing ramp aluminum objects located at adjacent slice positions. The middle aluminum plate of each image was automatically segmented. Next, the two segmented images were combined to produce one image with two stair objects. The centroid coordinates of two stair objects were automatically determined. Subsequently, the distance between these two centroids was measured to directly indicate the slice spacing. For comparison, the slice spacing was calculated by accessing the slice position attributes from the DICOM header of both images. The proposed method was tested on phantom images with variations in slice spacing and field of view (FOV). Results: The results showed that the automatic measurement of slice spacing was quite accurate for all variations of slice spacing and FOV, with average differences of 9.0% and 9.3%, respectively. Conclusion: A new automated method for measuring the slice spacing using the AAPM CT phantom was successfully demonstrated and tested for variations of slice spacing and FOV. Slice spacing measurement may be considered an additional parameter to be checked in addition to other established parameters.

Spectral CT image reconstruction using a constrained optimization approach-An algorithm for AAPM 2022 spectral CT grand challenge and beyond.

CT reconstruction is of essential importance in medical imaging. In 2022, the American Association of Physicists in Medicine (AAPM) sponsored a Grand Challenge to investigate the challenging inverse problem of spectral CT reconstruction, with the aim of achieving the most accurate reconstruction results. The authors of this paper participated in the challenge and won as a runner-upteam. This paper reports details of our PROSPECT algorithm (Prior-based Restricted-variable Optimization for SPEctral CT) and follow-up studies regarding the algorithm's accuracy and enhancement of its convergencespeed. We formulated the reconstruction task as an optimization problem. PROSPECT employed a one-step backward iterative scheme to solve this optimization problem by allowing estimation of and correction for the difference between the actual polychromatic projection model and the monochromatic model used in the optimization problem. PROSPECT incorporated various forms of prior information derived by analyzing training data provided by the Grand Challenge to reduce the number of unknown variables. We investigated the impact of projection data precision on the resulting solution accuracy and improved convergence speed of the PROSPECT algorithm by incorporating a beam-hardening correction (BHC) step in the iterative process. We also studied the algorithm's performance under noisy projectiondata. Prior knowledge allowed a reduction of the number of unknown variables by . PROSPECT algorithm achieved the average root of mean square error (RMSE) of in the test data set provided by the Grand Challenge. Performing the reconstruction with the same algorithm but using double-precision projection data reduced RMSE to . Including the BHC step in the PROSPECT algorithm accelerated the iteration process with a 40% reduction in computationtime. PROSPECT algorithm achieved a high degree of accuracy and computationalefficiency.

Comparison of visual and semi-automated kilovoltage cone beam CT image QA analysis.

Established kilovoltage cone-beam computed tomography (kV-CBCT) image quality assurance (QA) guidelines often rely on recommendations provided by the American Association of Physicists in Medicine (AAPM) task group (TG) reports with metrics that use visual analysis. This can result in measurement variations by different users, especially in visually subjective analyzes such as low contrast resolution. Consequently, there is a growing interest in more automated means of image QA analysis that can offer increased consistency, accuracy, and convenience. This work compares visual QA to semi-automated software QA analysis to establish the performance and viability of a semi-automated method. In this study, a commercial product (RIT Radia. Radiological Imaging Technology, Colorado Springs, CO) was used to evaluate 68 months of kV-CBCT images of a Catphan® 504 phantom obtained from a Varian TrueBeam® linear accelerator. Six key metrics were examined: high contrast resolution, low contrast resolution, Hounsfield unit constancy, uniformity and noise, and spatial linearity. The results of this method were then compared to those recorded visually using Bland-Altman, and/or paired sample t-test. Comparison of all modules showed a non-random, statistically significant difference between visual and semi-automated methods except for LDPE and Teflon in the Hounsfield unit constancy analysis, which falls outside the paired sample t-test's 5% significance level. A small high contrast resolution bias indicates the two analysis methods are largely equivalent, while a large low contrast resolution bias indicates greater semi-automated target detection. Wide limits of agreement in the uniformity module suggests variability due to multiple visual observers. Spatial linearity results measured differences of less than 0.17%. Semi-automated QA analysis offered greater stability over visual analysis. Additionally, semi-automated QA results satisfied or exceeded visual QA passing criteria and allowed for fast and consistent image quality analysis.

Best Practices for Artificial Intelligence and Machine Learning for Computer-Aided Diagnosis in Medical Imaging

The American Association of Physicists in Medicine (AAPM) Task Group (TG) 273 has been charged with developing recommendations on best practices for the development and performance assessment of computer-aided decision support systems. The TG report [1] addresses broad issues common to the development of most, if not all, CAD-AI applications and their translation from the bench to the clinic. The goal was to bring attention to issues such as proper data collection and training and validation methods for ML algorithms, aiming to improve generalizability and reliability and thus accelerate the adoption of CAD-AI systems for clinical decision support. The report focuses on several developmental stages of CAD-AI: data collection, reference standards, model development, performance assessment, and translation to the clinic.

MR-Linac Dosimetry: Current Approaches and Challenges

The use of MR-integrated linacs (MR-linac) in clinical radiation oncology applications are becoming more prevalent. However, given the novel and radically different designs of these systems from conventional linacs, current radiation dosimetry protocols for high energy photons are no longer appropriate for use in modern MR-linac systems: First, given the presence of the magnetic field and the linac design, traditional reference conditions defined by previous high energy photon dosimetry protocols cannot be met; Second, the presence of the strong magnetic field can affect the performance of conventional equipment used for dosimetry. In this manuscript, we describe some of the challenges faced in radiation dosimetry in external MR-guided radiotherapy delivery systems, summarize some of the publications in this area, and finally discuss the early work by the American Association of physicists in Medicine (AAPM) Task Group 351 which is mandated with producing a protocol for reference dosimetry in MR-linac units.

Comparative dosimetry of an epoxy resin pediatric head phantom and PMMA phantom for CT imaging

A pediatric head phantom was created using epoxy resin to evaluate the amount of radiation exposure in computed tomography (CT) scans. The phantom's size resembled that of a child's head, with a diameter of 10 cm and a length of 15 cm. A comparative analysis was conducted to examine and compare the atomic composition, effective atomic number, electron density, and mass density of the epoxy resin material with those of polymethyl methacrylate (PMMA). To measure the radiation dose received by the phantom, a 100 mm pencil ion chamber was used at both the center and periphery. The weighted CT dose index (CTDIw) and volumetric CT dose index (CTDIvol) were determined for various tube potentials, keeping the current-time product constant. A standard calibrated phantom was also used for a comparable analysis. The results indicated that the physical properties of the epoxy resin material were similar to PMMA, and the phantom demonstrated equivalent dosimetric performance to the PMMA phantom across all tube voltages. Lastly, the CTDIvol values obtained from the fabricated and standard phantoms were compared with the corresponding values displayed on the CT console. The differences fell within the limits set by the American Association of Physicists in Medicine (AAPM). These findings demonstrate that the cost-effective pediatric phantom offers a practical and economical approach to assessing the radiation dose in CT scans for children, while exhibiting dosimetric properties comparable to those of commercially available phantoms.

The implementation of an image-guided system at a proton therapy center facility.

Pencil Beam Scanning (PBS) proton therapy has similar requirements on patient alignment to within 1mm and 1-degree accuracy as photon radiosurgery. This study describes general workflow, acceptance, and commissioning test procedures and their respective results for an independent robotic arm used for Image Guided Radiotherapy (IGRT) for a Proton Therapy System. The system is equipped with kV-imaging techniques capable of orthogonal and Cone-Beam Computed Tomography (CBCT) imaging modalities mounted on an independent robotic arm gantry attached to the ceiling. The imaging system is capable of 360-degree rotation around patients to produce CBCT and kilovoltage orthogonal images. The imaging hardware is controlled by Ehmet Health XIS software, and MIM Software handles the image fusion and registration to an acceptable accuracy of ≤1-mm shifts for patients' alignment. The system was tested according to the requirements outlined in the American Association of Physicists in Medicine (AAPM) Task Group (TG) 142 and TG 179. The system tests included (1) safety, functionality, and connectivity, (2) mechanical testing, (3) image quality, (4) image registration, and (5) imaging dose. Additional tests included imaging gantry isocentricity with a laser tracker and collision-avoiding system checks. The orthogonal and volumetric imaging are comparable in quality to other commercially available On-Board Imagers (OBI) systems. The resulting spatial resolution values were 1.8-, 0.8-, and 0.5-Line Pairs per Millimeter (lp/mm) for orthogonal, full-fan CBCT, and half-fan CBCT, respectively. The image registration is accurate to within 1mm and 1 degree. The data shows consistent imaging-guided system performance with standard deviations in x, y, and z of 0.7, 0.8, and 0.7mm, respectively. The system provides excellent image quality and performance, which can be used for IGRT. The proven accuracy of the x-ray imaging and positioning system at McLaren Proton Therapy Center (MPTC) is 1mm, making it suitable for proton therapy.

Measurement of leakage radiation dose to patients undergoing chest x-ray in some x-ray facilities in Warri Town. Nigeria.

The increase in the application of x-ray in health management has necessitated the need to determine the risk associated with its use. This study is aimed at measuring the leakage radiation dose to patients undergoing chest x-ray in twenty (20) radiological facilities in Warri, Delta State. A portable GMC-600 digital Geiger Muller Counter (serial number: 36311386254310) was used to examine the facilities. The leakage radiation was measured from both the cathode and anode terminals of the machines across the facilities studied and their mean exposure readings were obtained. The leakage radiation (mR/hr) values for the cathode terminal ranges from 0.21 – 100.27 mR/hr with an average of 26.46 mR/hr while the anode terminal is from 0.21 – 99.70 mR/hr with an average of 24.88 mR/hr. From the obtained results, it was observed that only one machine, A10 (100.27 mR/hr) exceeded the recommended limit (100 mR/hr) for leakage radiation as stipulated by American Association of Physicist in Medicine (AAPM). This indicates that the workers and members of the public in the said facility could be exposed to some level of harmful radiations. 

A Prospective, Multi-Institutional Study of Problematic Plan Detection during Physician Chart Rounds.

We performed a multi-institutional prospective study to determine the detection rate of problematic treatment plans (PP) at physician chart rounds (CR), and to identify factors associated with PP detection. Curative intent PPs with simulated errors (representative of the most common targets of peer review) were generated. Two breast specialists selected twenty appropriate plans for inclusion and assigned them American Association of Physicists in Medicine (AAPM) Task Group 100 severity and detectability scores. The PPs were blinded and embedded at weekly virtual CR at 2 institutions over 12 months. At site A, both breast and lung cases were reviewed by a mix of breast and lung specialists during CR, and at site B, only breast cases were presented and reviewed by breast specialists. At both sites, breast plans were reviewed via slice-by-slice review in the treatment planning system (TPS), and both used a color-coded tool from the TPS to assess adherence to planning directives. Both sites had systematic approaches to case presentation (without a checklist). Site A was usually prospective CR, while site B was exclusively prospective. The following CR elements were recorded: PP detection, time of detection, length of CR, total number of cases presented, plan elements displayed, number and roles of attendees, and detector's role. Analysis was performed using simple statistics with chi-square testing. By PP error type classification, 55.0% pertained to "target volume delineation," 25% to "non-target volume delineation or normal tissue sparing," and 20.0% to "dose prescription or written directives." Detectability was rated ≤5 (<5% likelihood of going undetected) for 60% of PPs, and severity was rated ≥7 ("at least potentially serious toxicity or tumor underdose") for only 30% of PPs. CR lasted a median of 64 minutes at site A (IQR 55-82.5) and 70 minutes at site B (IQR 52.5-81.5). PPs were presented at a median of 34 minutes (IQR 22.5-43, site A) and 41.5 minutes (IQR 23.5-56, site B) after CR start. A median of 16 cases (IQR 13-19) at site A and 32 cases (IQR 25-34.5) at site B were presented per CR session, with a median of 1 PP (site A and B) presented per session (range 1-2). The median time spent per case was 4.0 minutes (Site A) and 2.2 minutes (Site B). The median number of attendings at CR was 4 for site A (range 2-6) and 6.5 for Site B (range 5-10). PP detection rate at site A was 20% (n = 4) and at site B was 70% (n = 14) (p = 0.001). Detections were made by an attending physician in 100% (site A, n = 4) and 92.9% (Site B, n = 13) of PP detections. There were no differences in detection rate by PP error type (p = 0.78), detectability (p = 0.60) or severity score (p = 0.68), or by time PP presented after CR start (p = 0.39). The effectiveness of PP detection at chart rounds can vary greatly between institutions. The study suggests possible areas for improvement but further study is needed to determine best practices.

Operational Ontology for Radiation Oncology (OORO): A Professional Society-Based, Multi-Stakeholder Consensus Driven Informatics Standard Supporting Clinical and Research Use of Real-World Data

There is a critical need for large-scale, multi-institutional "real-world" data to evaluate patient, diagnosis and treatment factors affecting oncology patient outcomes. However, lack of data standardization undermines the potential for automated learning from the vast amount of information routinely archived in electronic health records (EHRs), Radiation Oncology Information Systems and other cancer care databases. As next step to promote data standardization beyond the American Association of Physicists in Medicine (AAPM)'s TG-263 guidance for radiotherapy (RT) nomenclature, the AAPM's Big Data Subcommittee (BDSC) has led an international RT professional society collaboration to develop the Operational Ontology for Radiation Oncology (OORO). Initiated July 2019 to explore issues that typically compromise formation of large inter- and intra- institutional databases from EHRs, the AAPM's BDSC membership includes representatives from the AAPM, American Society of Radiation Oncology (ASTRO), Canadian Organization of Medical Physicists (COMP), Canadian Association of Radiation Oncology (CARO), European Society of Therapeutic Radiation Oncology (ESTRO) and clinical trials experts from NRG Oncology. Multiple external stakeholders were engaged, including government agencies, vendors and RT community members through the iterative and consensus-driven approach to OORO development. The OORO includes 42 key elements, 359 attributes, 144 value sets, and 155 relationships, ranked for priority of implementation based on clinical significance, likelihood of availability in EHRs, or ability to modify routine clinical processes to permit aggregation. The initial version of OORO includes many disease-site independent concepts common for all cancer patients and a smaller set specific for prostate cancer. The OORO development methodology is currently being applied/adapted to include additional disease site-specific concepts beginning with head and neck cancers. The first of its kind in radiation oncology, the OORO is a professional society-based, multi-stakeholder, consensus driven informatics standard. The iterative and collaborative approach to ontology development and refinement aims to ensure that OORO serves as a « living » guidance document, facilitating incremental expansion of data elements over time, as disease site-specific standards are set and RT concepts evolve. Supporting construction of comprehensive "real-world" datasets and application of advanced analytic techniques, including artificial intelligence (AI), OORO holds the potential to revolutionize patient management and improve outcomes.

Quality and Safety Considerations in Image Guided Radiation Therapy: An ASTRO Safety White Paper Update

This updated report on image guided radiation therapy (IGRT) is based on a consensus-based white paper previously published by the American Society for Radiation Oncology (ASTRO) addressing patient safety. In the past decade, IGRT technology and procedures have progressed significantly and are now more commonly used. The use of IGRT has now extended beyond high-precision treatments, such as stereotactic radiosurgery and stereotactic body radiation therapy, and into routine clinical practice for many treatment techniques and anatomic sites. Therefore, quality and treatment planning and delivery considerations for these techniques are paramount for patient safety. In 2021, ASTRO convened an interdisciplinary task force to assess the original IGRT white paper and update content where appropriate. Recommendations were created using a consensus-building methodology, and task force members indicated their level of agreement based on a 5-point Likert scale from "strongly agree" to "strongly disagree." A prespecified threshold of ≥75% of raters who selected "strongly agree" or "agree" indicated consensus. The IGRT white paper was published (Pract Radiat Oncol. 2022 Dec) and endorsed by the American Association of Physicists in Medicine (AAPM), American Association of Medical Dosimetrists, and American Society of Radiologic Technologists. Since the first IGRT paper was published by ASTRO in 2013, significant technological advancement has taken place. New and updated considerations in personnel requirements, staffing, education and training, equipment and technological requirements, quality management and assurance, IGRT program management, and safety considerations were reported. A 17-point consensus was reached and recommended in 5 areas surrounding program development, quality assurance, quality management, treatment delivery, and vendor engagement (Table 5, Summary of key recommendations). This IGRT white paper builds on the previous version and uses other guidance documents to primarily focus on processes related to quality and safety. IGRT requires an interdisciplinary team-based approach, staffed by appropriately trained specialists, as well as significant personnel resources, specialized technology, and implementation time. A thorough feasibility analysis of resources is required and should be discussed with all personnel before undertaking new imaging techniques. A comprehensive quality-assurance program must be developed to ensure IGRT is performed safely and effectively. As IGRT technologies continue to improve or emerge, existing practice guidelines should be updated regularly according to the latest AAPM Task Group reports. Patient safety in the application of IGRT is everyone's responsibility, and professional organizations, regulators, vendors, and end-users must demonstrate strong commitments to ensure that the highest levels of safety are achieved.

AAPM Medical physics practice guideline 15.A: Peer review in clinical physics.

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 8000 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 use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. While must is the term to be used in the guidelines, if an entity that adopts the guideline has shall as the preferred term, the AAPM considers that must and shall have the same meaning. Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances.

Generation and comparison of 3D dosimetric reference datasets for COMS eye plaque brachytherapy using model-based dose calculations.

A joint Working Group of the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) was created to aid in the transition from the AAPM TG-43 dose calculation formalism, the current standard, to model-based dose calculations. This work establishes the first test cases for low-energy photon-emitting brachytherapy using model-based dose calculation algorithms (MBDCAs). Five test cases are developed: (1) a single model 6711 125 I brachytherapy seed in water, 13 seeds (2) individually and (3) in combination in water, (4) the full Collaborative Ocular Melanoma Study (COMS) 16 mm eye plaque in water, and (5) the full plaque in a realistic eye phantom. Calculations are done with four Monte Carlo (MC) codes and a research version of a commercial treatment planning system (TPS). For all test cases, local agreement of MC codes was within ∼2.5% and global agreement was ∼2% (4% for test case 5). MC agreement was within expected uncertainties. Local agreement of TPS with MC was within 5% for test case 1 and ∼20% for test cases 4 and 5, and global agreement was within 0.4% for test case 1 and 10% for test cases 4 and 5. Dose distributions for each set of MC and TPS calculations are available online (https://doi.org/10.52519/00005) along with input files and all other information necessary to repeat the calculations. These data can be used to support commissioning of MBDCAs for low-energy brachytherapy as recommended by TGs 186 and 221 and AAPM Report 372. This work additionally lays out a sample framework for the development of test cases that can be extended to other applications beyond eye plaque brachytherapy.