Molecular Imaging Informed Radiation Dose Escalation to Sites of Recurrent Disease and De-escalation to Uninvolved Areas in Salvage Radiotherapy Using SBRT for Prostate Cancer to Reduce Treatment Toxicity

This is a single arm trial that is recruiting a total of 50 participants that have been diagnosed with prostate bed (where the prostate was taken out) or regional (surrounding lymph nodes) recurrence of a prostate cancer following surgery. Salvage radiation treatment represents the main treatment option, with long-term cure rates on the order of 70%. Currently, salvage radiation treatment to the prostate bed and the pelvic lymph nodes is delivered using external beam radiation therapy (EBRT) in 20-33 sessions, over 4-6.5 weeks. Potential study participants have undergone a PSMA PET scan, which has found recurrent cancer in the prostate bed or lymph nodes. This study will investigate personalizing your radiation treatment based on this information. Participants on this study will receive lower than standard radiation dose to areas of the surgical site which do not show evidence of disease on the scan.

This personalized radiotherapy will be delivered in 5 treatments over two weeks, rather than the four to 6 weeks which is the current standard of care. Participants will have a routine history, blood collection for PSA and hormone levels, toxicity assessment, and EPIC-26 \& IPSS questionnaires at each follow-up visit. These will take place at 1, 3, 6, 12, 24, 36, and 60 months after radiation treatment.