Predictors of PSMA PET Positivity: Analysis in a Selected Cohort of Biochemical Recurrence Prostate Cancer Patients after Radical Prostatectomy

SIMPLE SUMMARY: Localized prostate cancer can be treated with radical intent via surgery, yet up to 50% of patients experience a rise in prostate-specific antigen (PSA) serum levels during the post-surgical follow-up, a condition defined as a biochemical recurrence that requires additional examinations and treatments. PSMA PET is the most accurate diagnostic tool to detect disease recurrence in patients with biochemical recurrence. In the present work, a retrospective analysis of a selected cohort of patients with biochemical recurrence has been performed to explore potential predictors of PSMA PET positivity. We observed that pT3a or higher pathological status after radical prostatectomy, and high levels of PSA at the time of scan are significantly correlated with PSMA PET positivity. These findings may contribute to an optimization in the management of biochemical recurrence patients, via a better patient selection and imaging timing. ABSTRACT: Localized prostate cancer (PCa) can be treated with radical prostatectomy (RP). Up to 30% of patients undergoing this procedure experience biochemical recurrence (BCR), namely the rise in serum prostate-specific antigen (PSA) levels during the post-surgical follow-up, requiring further treatments and with the risk of severe disease progression. Currently, the most accurate imaging technique to confirm, detect, and locate disease relapses in BCR patients is prostate-specific membrane antigen (PSMA)-targeted PET, as recommended by international clinical guidelines. The aim of the study was to investigate potential clinical and pathological predictors of PSMA PET positivity, validated by clinical and instrumental follow-up or histopathological data. In this study, a selected cohort of BCR patients after RP and no other PCa-related therapy who underwent either PSMA PET/CT or PSMA PET/MRI has been analysed. Among the considered predictors, both pathological staging after RP equal or higher than pT3a and higher PSA levels at the time of the scan were significantly correlated with PSMA PET positivity on multivariate logistic regression analysis. As expected, PSMA PET confirmed its role as an accurate imaging technique in the setting of BCR in PCa. These findings may inform appropriate and tailored patient selection and scan timing to optimize and fully exploit this powerful diagnostic tool.