AAPM Task Group 264: The safe clinical implementation of MLC tracking in radiotherapy.

The era of real-time radiotherapy is upon us. Robotic and gimbaled linac tracking are clinically established technologies with the clinical realization of couch tracking in development. Multileaf collimators (MLCs) are a standard equipment for most cancer radiotherapy systems, and therefore MLC tracking is a potentially widely available technology. MLC tracking has been the subject of theoretical and experimental research for decades and was first implemented for patient treatments in 2013. The AAPM Task Group 264 Safe Clinical Implementation of MLC Tracking in Radiotherapy Report was charged to proactively provide the broader radiation oncology community with (a) clinical implementation guidelines including hardware, software, and clinical indications for use, (b) commissioning and quality assurance recommendations based on early user experience, as well as guidelines on Failure Mode and Effects Analysis, and (c) a discussion of potential future developments. The deliverables from this report include: an explanation of MLC tracking and its historical development; terms and definitions relevant to MLC tracking; the clinical benefit of, clinical experience with and clinical implementation guidelines for MLC tracking; quality assurance guidelines, including example quality assurance worksheets; a clinical decision pathway, future outlook and overall recommendations.

AAPM medical physics practice guideline 7.a.: Supervision of medical physicist assistants.

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 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. Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances. Approved by AAPM's Executive Committee May 28, 2019.

Code of ethics for the American Association of Physicists in Medicine (Revised): Report of Task Group 109.

The American Association of Physicists in Medicine (AAPM) has established a comprehensive Code of Ethics for its members. The Code is a formal part of AAPM governance, maintained as Professional Policy 24, and includes both principles of ethical practice and the rules by which a complaint will be adjudicated. The structure and content of the Code have been crafted to also serve the much broader purpose of giving practical ethical guidance to AAPM members for making sound decisions in their professional lives. The Code is structured in four major parts: a Preamble, a set of ten guiding Principles, Guidelines that elucidate the application of the Principles in various practice settings, and the formal Complaint process. Guidelines have been included to address evolving social and cultural norms, such as the use of social media and the broadening scope of considerations important in an evolving workplace. The document presented here is the first major revision of the AAPM Code of Ethics since 2008. This revision was approved by the Board of Directors to become effective 1 January 2019.

Experimental comparison of seven commercial dosimetry diodes for measurement of stereotactic radiosurgery cone factors.

PURPOSE: The purpose of this work is to assess the variation in performance of various commercially available dosimetry diodes for quantitative small field dosimetry, specifically by intercomparing measurements of SRS cone factors. METHODS: Measurements were made in 6 MV photon beams with fixed SRS cones for two accelerator-based SRS systems: a Varian Clinac iX (Varian/Zmed cones) at 600 MU/min and a CyberKnife model G4 at 800 MU/min. Measurements were made at 1.5 cm depth in water using the IBA Dosimetry "blue phantom" 3D scanning system, controlled by OMNIPRO-ACCEPT software. Source-to-detector distance was 100 cm for the Clinac, 80 cm for the CyberKnife. Two normalization methods were used for the Clinac, one directly referenced to diode measurements in a 10 cm x 10 cm square field and the other indirectly by "daisy-chaining" diode measurements to ion chamber measurement in the 10 cm x 10 cm reference field through an intermediate 4 cm x 4 cm square field. CyberKnife factors were referenced directly to measurements in the 60 mm reference field. Seven commercial diodes were evaluated: PTW TN60008, TN60012, TN60016, TN60017; IBA Dosimetry SFD; Sun Nuclear EDGE; Exradin SD1 (first generation prototype). RESULTS: With the exception of the SFD, all the evaluated devices yielded surprisingly consistent results. Standard deviations of Clinac factors for four diodes (SD1, EDGE, TN60008, and TN60012) ranged from approximately 0.50% at 30 mm to 2.0% at 5 mm cones size when referenced directly to the 10 cm x 10 cm measurement. The daisy-chaining strategy reduced the standard deviation to approximately 0.30% at 30 mm and 1.9% at 5 mm. Standard deviations for the same four diodes in the CyberKnife beam ranged up to approximately 1.0% at 5 mm. CONCLUSIONS: The inter-detector variation is small and appears to be systematic with detector packaging, more inherent filtration producing flatter curves for both the relatively hard Clinac beam and the softer CyberKnife beam. The daisy-chain strategy appears to be of limited value for most of the diodes, but does bring the SFD results into significantly better agreement with the others.

Code of Ethics for the American Association of Physicists in Medicine: report of Task Group 109.

A comprehensive Code of Ethics for the members of the American Association of Physicists in Medicine (AAPM) is presented as the report of Task Group 109 which consolidates previous AAPM ethics policies into a unified document. The membership of the AAPM is increasingly diverse. Prior existing AAPM ethics polices were applicable specifically to medical physicists, and did not encompass other types of members such as health physicists, regulators, corporate affiliates, physicians, scientists, engineers, those in training, or other health care professionals. Prior AAPM ethics policies did not specifically address research, education, or business ethics. The Ethics Guidelines of this new Code of Ethics have four major sections: professional conduct, research ethics, education ethics, and business ethics. Some elements of each major section may be duplicated in other sections, so that readers interested in a particular aspect of the code do not need to read the entire document for all relevant information. The prior Complaint Procedure has also been incorporated into this Code of Ethics. This Code of Ethics (PP 24-A) replaces the following AAPM policies: Ethical Guidelines for Vacating a Position (PP 4-B); Ethical Guidelines for Reviewing the Work of Another Physicist (PP 5-C); Guidelines for Ethical Practice for Medical Physicists (PP 8-D); and Ethics Complaint Procedure (PP 21-A). The AAPM Board of Directors approved this Code or Ethics on July 31, 2008.