A Prospective Provincial Registry of 18F-PSMA PET/CT for Recurrent Prostate Cancer: Results for 4,135 Men

The PSMA-PET Registry for Recurrent Prostate Cancer study was initiated in Ontario, Canada, to provide access to and characterize the performance of 18F-prostate-specific membrane antigen (PSMA) PET/CT among men with recurrent prostate cancer. Methods: Between October 2018 and September 2022, 4,135 men were enrolled in PREP. Eligibility included suspected prostate cancer recurrence after prior definitive treatment (radical prostatectomy or radiotherapy). Men were enrolled in 1 of 6 predefined clinical cohorts and imaged with 18F-DCFPyL at 1 of 6 participating sites. Standardized reports delineated sites of recurrence and changes in disease management after PET/CT. Linkage to provincial databases allowed estimation of overall survival (OS) and use of salvage radiotherapy after PET/CT. Results: The median follow-up was 1.8 y. Significant predictors of a positive PET/CT scan on multivariate analysis included a higher prostate-specific antigen level at the time of PET/CT and cohort (highest for cohort 4, whose cancer had progressed during salvage hormone therapy). Significant predictors of management change were type of recurrence (highest for isolated locoregional disease) and higher prostate-specific antigen level. Significant predictors of worse OS included cohort (worst for cohort 4) and extent and type of metastases (worst for mixed bone, lymph, and visceral or extensive metastases). A change in disease management after PET/CT was a significant independent predictor of improved OS rates. Conclusion: PREP facilitated access to 18F-PSMA PET/CT and demonstrated high rates of disease detection. Significant factors associated with survival were clinical scenario, pattern of metastases, and change in disease management after 18F-PSMA PET/CT.