Phase II Trial of PSA Response-based Androgen Deprivation Therapy and Nodal Coverage for Prostate Cancer Early Salvage Radiotherapy (RANGER)

Inclusion Criteria: * Men aged ≥18 years with histologically confirmed prostate adenocarcinoma treated with prostatectomy in the localized setting within 10 years, with post-operative PSA (persistent or rising) of ≥0.05ng/mL. * Radical prostatectomy ≥4 months prior to enrollment without nodal involvement (pN0 or pNx) * Performance status ECOG 0-2 * No definite evidence of regional or distant metastatic disease by at least pelvic imaging within 90 days of registration. Equivocal findings are allowed at investigator discretion. Imaging is specified as follows: * PSA\>=0.2ng/mL: positron emission tomography (PET) with FDA-approved advanced imaging agent for prostate cancer (e.g. PSMA) required. * PSA \<0.2 n/gm: PET with above noted agents OR conventional CT or MRI at investigator discretion. * All sexually active men must agree to use adequate contraception for the duration of study therapies and a period of 60 days thereafter. Should a female partner of a trial participant become pregnant or suspect she is pregnant while the subject is participating in this study, the patient should inform his treating physician immediately. * Ability to understand and the willingness to sign a written informed consent. Exclusion Criteria: * Prior androgen deprivation therapy (ADT) \> 3 months OR anti-androgen therapy (AAT) of \> 30 days. For shorter courses of either, at least 30 day "wash out" period is required with confirmation of resolved castration of testosterone to \>50ng/mL. * Ongoing testosterone replacement therapy (TRT) with refusal to discontinue (must be stopped with demonstration of detectable PSA ≥0.05ng/mL and non-castrate testosterone \>50ng/mL after 14 days of TRT cessation) * Prior pelvic radiotherapy * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that, in the opinion of the investigator, would limit compliance with study requirements. * History of bladder neck or urethral stricture requiring procedural intervention. * Patients with a prior or concurrent malignancy whose natural history or treatment has the potential to actively interfere with the safety or efficacy assessments of this study in the investigator's view. * Active inflammatory bowel disease requiring recurring systemic or steroid/enema therapy