Patterns of recurrence post prostatectomy in the PSMA era: What lessons can we take to daily practice from a high-volume nuclear medicine center?

Abstract

e17013 Background: PSMA has deeply modified the treatment of prostate cancer, mainly in the biochemical recurrence setting, where the therapeutic plan may be changed in up to two thirds of cases. Unfortunately, this diagnostic tool is still not fully available in many places over the world. Growing evidence from high-volume nuclear medicine centers may guide the development of adapted treatment plans based on sites of relapse according to wide available clinical information. Methods: We retrospectively reviewed 648 Ga68-PSMA-PET-CT scans in the biochemical relapse setting in patients initially treated with prostatectomy. Results were classified either as negative or positive if abnormal SUV uptake was detected in the prostate bed, pelvis, or distant organs. We then classified the patients with positive tests based on sites of relapse according to serum PSA level. Results: Among the 648 analyzed patients, there were 60, 63, and 61 recurrences in prostate bed, pelvis, or distant organs, respectively. For those with serum PSA ≤ 1.0 ng/mL, there was a higher chance of locoregional failure (prostate bed or pelvis), with less than 20% presenting distant metastasis. When assessing patients with serum PSA 1.1-2.0 ng/mL, the rate of distant metastasis increased to 22.7%, while it was found in 40.7% of patients with serum PSA between 2 and 5 ng/mL. Conclusions: PSMA-PET-CT scan is clearly modifying the therapeutic landscape of prostate cancer in different scenarios. Although it is not available in many regions due to high financial costs and logistic barriers, the emerging evidence arising from specialized cancer centers matching the clinical information with tests results may help doctors to make better treatment decisions even without PSMA-PET-CT scans. [Table: see text]