Prostate Cancer Postoperative Stereotactic Body Radiotherapy With Adaptive Technology for Minimizing Toxicity

Single-arm, prospective registry study assessing changes in acute patient-reported urinary (GU) and gastrointestinal (GI) quality of life at the 24-month post-treatment time point following magnetic resonance imaging (MRI)-guided or computed tomography (CT)-guided stereotactic body radiotherapy (SBRT) delivered to the prostate bed +/- pelvic lymph nodes. The decision to offer an adaptive treatment will be at the clinician's discretion.

Inclusion Criteria * History of histologically confirmed, clinical localized adenocarcinoma of the prostate treated with radical prostatectomy with definitive intent. * Presence of any ONE of the following: 1. Adverse pathologic features at the time of prostatectomy (positive surgical margin, pathologic T-stage 3-4 disease, pathologic Gleason score 8-10 disease, OR presence of tertiary Gleason grade 5 disease) 2. Documentation of rising prostate-specific antigen on at least two consecutive draws, with the magnitude of prostate-specific antigen exceeding 0.03 ng/mL 3. Intermediate- or high-risk Decipher genomic classifier score 4. Identification of prostate cancer in ≥1 lymph node at the time of prostatectomy (pN+ disease) * CT scan and MRI of the pelvis within 120 days prior to enrollment \[note: (a) if patient has medical contraindication to MRI, an exemption will be granted and enrollment can proceed; (b) for patients with PSA \1.0 ng/mL. * Age ≥ 18. \~. KPS ≥ 70 and/or ECOG \