The oligometastatic disease state is an increasingly recognized phenomenon in prostate cancer. Ga-68 PSMA PET/CT has high accuracy in the diagnosis metastases from prostate cancer. In this protocol, pretreatment Ga-68 PSMA PET/ CT shall be performed in all patients.~ADT is considered standard of care treatment for advanced prostate cancer. But hormonal therapy can have side effects that greatly trouble men and lead to castration-resistant prostate cancer (CRPC). Any effort to delay the start of hormonal therapy would be an advantage to the patient. Stereotactic body radiation therapy (SBRT) is highly focused radiation, given in a very dose intensive fashion and delivered in usually less than one week. SBRT has been shown to be very effective on bone or lymph nodes metastases. Therefore, we are studying the safety and feasibility of SBRT on patients with five or fewer prostate cancer bone or lymph nodes metastases to determine if we can stall the use of hormonal therapy and/or prevent other site metastases from developing elsewhere in the body.
The aim of this study is to test the safety and feasibility of SBRT without ADT in oligometastatic prostate cancer in patients for whom the standard treatment is ADT, and to further explore how long only radiotherapy for oligometastases can prolong biochemical progression-free survival (bPFS). In this study, men with oligometastatic prostate cancer lesions will be randomized (1:1) to ADT versus SBRT. Within 6 weeks of the oligometastases diagnosis, ADT or SBRT (30-50Gy with 3-5 fractions) will be administered.