In Regard to the Science Council and Therapy Physics Committee of AAPM

Abstract

To the Editor: We thank the Science Council and Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) ( 1 The Science Council and Therapy Physics Committee of the American Association of Physicists in MedicineIndependent phantom irradiation is both necessary and cost effective for clinical trial credentialing. Int J Radiat Oncol Biol Phys. 2015; 92: 501-503 Abstract Full Text Full Text PDF Scopus (4) Google Scholar ) for their interest in the National Cancer Institute workshop on radiation therapy quality assurance (QA), which is summarized in reference ( 2 Bekelman J.E. Deye J.A. Vikram B. et al. Redesigning radiotherapy quality assurance: Opportunities to develop an efficient, evidence-based system to support clinical trials—Report of the National Cancer Institute Work Group on Radiotherapy Quality Assurance. Int J Radiat Oncol Biol Phys. 2012; 83: 782-790 Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar ). We agree that the use of physical phantoms is important to assure that the planned and delivered dose are both in agreement with one another and with the requirements of trial protocols as well as the expectations of clinical practice. Thus it would be a significant misinterpretation of our recommendations to assume that such phantom tests can be replaced by digital phantoms along the whole continuum of clinical trials from early to late phase. Physical phantoms play a very important role in the early-stage development and use of advanced technologies, including many that are used in radiation therapy. However, as the technology matures, though anthropomorphic phantoms may still be required for clinical practice accreditation, their use can be curtailed for clinical trial participation because it is not the scientific or ethical role of clinical trial research to ensure practice standards. Practice standards must demand zero tolerance for errors in patient treatments, whereas a scientific hypothesis can be assessed with some patient data as statistical outliers. Thus the workshop discussion led to the recommendation that QA required for clinical trial participation should be no more restrictive than the statistical demands of the trial design, which led to the recommendation for a tiered approach to credentialing: tier 1, general; tier 2, trial-specific; and tier 3, individual case reviews. Although phantom irradiation may help to identify those outliers who have not properly planned or delivered the protocol treatment, it was suggested that there may be other ways to achieve this statistical goal such as “biomarkers (that) could be used to guide QA efforts” or through a more thorough analysis of adverse events by participating institution. We must emphasize that clinical trial research should never be used to ensure practice standards, as we are certain that the Science Council as well as the Therapy Physics Committee of the AAPM agree. Independent Phantom Irradiation Is Both Necessary and Cost Effective for Clinical Trial CredentialingInternational Journal of Radiation Oncology, Biology, PhysicsVol. 92Issue 3PreviewThe Science Council and Therapy Physics Committee (TPC) of the American Association of Physicists in Medicine (AAPM) applaud the report by Bekelman et al (1) and support the overarching goal of examining “challenges and opportunities for optimizing radiotherapy quality assurance (QA) in clinical trial design.” The AAPM TPC includes an ad hoc committee, which provides scientific oversight of the activities of the Imaging and Radiation Oncology Core-Houston (IROC-Houston), which was formerly the Radiological Physics Center. Full-Text PDF