PRIMARY OBJECTIVE:~I. To compare the outcome of patients with unfavorable intermediate (IR) and high-risk (HR) prostate cancer (PCa) after standard dRT versus prostate-specific membrane antigen (PSMA) positron emission tomography (PET)-based dRT.~OUTLINE: Patients are randomized to 1 of 2 arms. In both arms, no other primary treatment should be given before RT.~Arm I: Patients do not undergo PSMA PET for dRT planning. Patients undergo standard of care dRT at the discretion of the treating radiation oncologist.~Arm II: Patients undergo PSMA PET for dRT planning. Patients then undergo dRT at the discretion of the treating radiation oncologist, who receives the PSMA PET result and images.~After completion of dRT, clinical follow-up of patients with their treating radiation oncologist will be obtained for 5 years. The investigators will rely on the medical records obtained from the treating physicians as the primary source of outcome data.
This randomized phase III trial studies the success rate of definitive radiation therapy (dRT) for prostate cancer (PCa) with or without planning based on PSMA PET. PSMA- PET-based dRT, may improve radiation therapy planning and patient selection for dRT, and potentially improve its outcome compared to dRT without PSMA PET (standard dRT).