Timing of Post-prostatectomy PSMA Imaging

The investigators will randomize patients presenting with early BCR with a negative baseline PSMA PET/CT, to upfront SRT or surveillance. Early BCR is defined as a PSA relapse of \>0.1 to \<0.3 ng/mL. Patients in the surveillance arm will be monitored with PSA every 3 months. A repeat PSMA PET/CT will be undertaken when the PSA reaches a target level of \>0.5 to \<1.0 ng/mL. Both early radiation treatment and surveillance with repeat PSMA PET/CT imaging are within patterns of practice locally; therefore, the investigators believe that there is clinical equipoise on this subject.