Use of Focal Radiotherapy Boost for Prostate Cancer and Perceived Barriers toward its Implementation: A Survey

Background In a recent phase III randomized control trial (FLAME), delivering a focal radiotherapy (RT) boost to tumors visible on MRI was shown to improve outcomes for prostate cancer patients without increasing toxicity. The aim of this study was to assess how widely this technique is being applied in current practices as well as physicians’ perceived barriers toward its implementation. Methods An online survey assessing the use of intraprostatic focal boost was conducted on RedCAP in December 2022. The survey link was distributed to radiation oncologists worldwide via email list, group text platform, and social media. Results The survey collected 205 responses from various countries over a two-week period. The majority of respondents worked at an academic medical center (59%) and considered their practice to be at least partially genitourinary (GU)-subspecialized (81%). 51% of participants reported not routinely using intraprostatic focal boost. Even among complete subspecialists, a substantial proportion (38%) do not routinely use focal boost. Less than half of participants in both high-income and low-to-middle-income countries were shown to routinely use focal boost. The most commonly cited barriers overall were challenges to accessing high-quality MRI, concerns about registration accuracy between MRI and CT, and concerns about risk of additional toxicity. Conclusion Despite the promising level 1 results of the FLAME trial, there is substantial evidence that most radiation oncologists are not routinely offering focal RT boost. Adoption of this technique might be accelerated by increased access to high-quality MRI, better registration algorithms of MRI to CT simulation images, physician education on benefit-to-harm ratio, and physician training on contouring prostate lesions on MRI. ### Competing Interest Statement TMS reports honoraria from Varian Medical Systems and WebMD; he has an equity interest in CorTechs Labs, Inc. and serves on its Scientific Advisory Board; he has received in-kind research support from GE Healthcare via a research agreement with the University of California San Diego. These companies might potentially benefit from the research results. The terms of this arrangement have been reviewed and approved by the University of California San Diego in accordance with its conflict-of-interest policies. ### Funding Statement This work was supported, in part, by the National Institutes of Health (NIH/NIBIB K08EB026503, NIH UL1TR000100), the American Society for Radiation Oncology, and the Prostate Cancer Foundation. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Institutional Review Board of UC San Diego waived ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.