Use of focal radiotherapy boost for prostate cancer and perceived barriers toward its implementation: a survey

Abstract

BackgroundIn 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.MethodsAn 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.ResultsThe 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.ConclusionDespite 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.

Clinical Impact of Contouring Variability for Prostate Cancer Tumor Boost

“…Nonetheless, of the 3 cases that allowed for comparison of contours with and without RSIrs, 2 cases showed a statistically significant improvement in ΔBF and ΔD98 with RSIrs. Other strategies to improve contouring accuracy for MRI-visible prostate tumors include involvement of expert radiologists in target delineation and dedicated training for radiation oncologists [12,13]. Alternative imaging modalities like PSMA PET may also prove useful [14][15][16][17][18].…”