RecruitingRadiation therapyTrial Evaluating the Safety and Efficacy Of MR-Linac-Guided Radiotherapy as Salvage Treatment After External Beam Radiotherapy Recurrence (TUMORNATOR II)The purpose of this study is to assess the impact of prostate-specific membrane antigen/positron emission tomography (PSMA/PET)-informed magnetic resonance (MR)-guided radiation therapy on serious toxicity outcomes in patients with biopsy-proven locally radiorecurrent prostate cancer. The primary aim is to evaluate the safety of delivering MR-Linac-guided stereotactic body radiotherapy (SBRT) after prior prostate external beam radiotherapy for recurrent disease, and assess urinary toxicity outcomes at 2 years.