Radiation Therapy for Metastatic Prostate Cancer

Inclusion Criteria: * Participant must be ≥ 18 years of age. * Participant must have an ECOG performance status ≤ 1. * Histologic confirmation of prostate adenocarcinoma of the prostate gland, with evidence of metastasis on imaging by conventional imaging (MRI, CT, or 99mTc bone scan) or PSMA PET/CT. Biopsy of sites of metastasis is strongly encouraged, but not required. * There must be at least 10-15 unstained slides from 2 cores of the highest tumor cellularity available. * Newly diagnosed disease with no prior treatment(surgery, radiation or systemic treatment, ie hormone therapy or chemotherapy) to the primary disease. * Participants may have started LHRH agonist or antagonist therapy, and/or androgen receptor signaling inhibitor (ARSI) as long as it was not started more than 30 days before the participant is enrolled on this study. * In participants who undergo only conventional imaging, oligometastatic disease is defined as 1-5 discrete metastatic sites in the bone and/or extra-pelvic lymph node (LN) stations. * Extra-pelvic LN stations are superior to the regional/pelvic LN stations. Pelvic LN stations commence at the bifurcation of the aorta and bifurcation of the proximal inferior vena cava to the common iliac veins. * Radiographic criteria for a LN to be considered a metastatic focus is defined as short-axis diameter in the axial plane of ≥ 1.0 cm, with irregular border and/or heterogeneous morphology * In participants who undergo PSMA PET/CT (in the presence or absence of conventional imaging), oligometastatic disease is defined as 1-10 PSMA avid bone lesions and/or extra-pelvic LN stations. The MI-RADS reporting system will be followed to guide PSMA PET interpretation * In participants extra-pelvic nodal (M1a) disease only by PSMA PET/CT and M0 by conventional imaging (i.e. extra-pelvic LN did not meet size criteria by CT), participant must meet 2 of 3 following criteria in order to be eligible: * 1\. PSA ≥ 40 * 2\. Evidence of cN1 disease (pelvic LN) * 3\. Decipher score ≥ 0.89 * Adequate organ and marrow function to receive treatment per treating physician * Medically fit for treatment and agreeable to follow-up. * Ability to understand and the willingness to sign a written informed consent. Exclusion Criteria: Participants with the presence of any of the following: * Castration resistant prostate cancer (CRPC). * Evidence of visceral or intracranial metastases. * Participant receiving any other investigational agents for cancer. * Participant is participating in a concurrent treatment protocol for cancer. * Unable to lie flat during or tolerate PET/MRI, PET/CT or SBRT. * Prior definitive treatment to the primary prostate cancer or pelvis. * Participant with uncontrolled intercurrent illness including, but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, uncontrolled diabetes (HgA1c \> 10), active pituitary or adrenal dysfunction, or psychiatric illness/social situations that would limit compliance with study requirements * History of another active malignancy within the previous 2 years, except for non-melanoma skin cancer, non-muscle invasive bladder cancer, or a malignancy that is considered cured with minimal risk of recurrence * Active Crohn's disease or ulcerative colitis despite medical management. * Refusal to sign informed consent. * Any condition that in the opinion of the investigator would preclude participation in this study