Impact of⁶⁸Ga-PSMA-11 PET on the Management of recurrent Prostate Cancer in a Prospective Single-Arm Clinical Trial

Objectives: Prostate-specific membrane antigen ligand positron emission tomography (PSMA PET) induces management changes in patients with prostate cancer. We aim to better characterize the impact of PSMA PET on management of recurrent prostate cancer in a large prospective cohort.

Methods: We report management changes following PSMA PET, a secondary endpoint of a prospective multicenter trial in men with prostate cancer biochemical recurrence. Pre-PET (Q1), Post-PET (Q2) and Post-Treatment (Q3) questionnaires were sent to referring physicians recording suspected site of recurrence, intended and implemented therapeutic and diagnostic management.

Results: Q1/Q2 response was collected for 382/635 (60%, intended cohort), Q1/Q2/Q3 for 206 patients (32%, implemented cohort). Intended management change occurred in 260/382 (68%) patients. Intended change was considered major in 176/382 (46%) patients. Major changes occurred most often for patients with PSA of 0.5 to <2.0 ng/mL (81/147, 55%). By analysis of stage-groups, management change was consistent with PET disease location, i.e. majority of major changes towards active surveillance (47%) for unknown disease site (103/382, 27%), towards local/focal therapy (56%) for locoregional disease (126/382, 33%), and towards systemic therapy (69% M1a; 43% M1b/c) for metastatic disease (153/382, 40%). Intended management was implemented in 160/206 (78%) patients. A total of 150 intended diagnostic tests, mostly CT (n=43, 29%) and bone Scans/NaF-PET (n=52, 35%), were prevented by PSMA PET; 73 tests, mostly biopsies (n=44, 60%) as requested by the study protocol, were triggered.

Conclusions: According to referring physicians, sites of recurrence were clarified by PSMA PET and disease localization translated into management changes in more than half of patients with biochemical recurrence of prostate cancer.