An Investigational Scan (rhPSMA-7.3 PET/CT) for Detecting Biochemically Recurrent Prostate Cancer, ENLIGHTEN Trial

PRIMARY OBJECTIVE: I. Determine consensus detection rate by flotufolastat F-18 gallium (rhPSMA-7.3)-PET (POSLUMA) scan in men with recent negative non-POSLUMA PET prostate specific membrane antigen (PSMA) scans. SECONDARY OBJECTIVES: I. Determine patient level verified detection rates (by histopathology or a surrogate standard of truth \[second contemporaneous imaging, treatment response/change in subsequent imaging\]). II. Determine change in management plan based on POSLUMA scan (major / minor). EXPLORATORY OBJECTIVE: I. Determine patient and patient disease characteristics consistent with a positive POSLUMA scan at prostate specific antigen (PSA) \< 0.5ng/ml (i.e. pathological Gleason grade, PSA at scan, time to biochemical recurrence \[BCR\], prostate-specific antigen doubling time \[PSADT\]). OUTLINE: Patients receive rhPSMA-7.3 intravenously (IV) and undergo PET/CT 60 minutes later on day 1. After completion of study intervention, patients are followed up at 14 days and then every 3 months for 2 years.