Baseline PSMA‐PET/CT as a predictor of PSA persistence following radical prostatectomy in high‐risk nonmetastatic prostate cancer patients receiving neoadjuvant therapy

Abstract

AbstractBackgroundThe precise staging and proper management of high‐risk prostate cancer (PCa) continues to be a challenge. We aimed to demonstrate the prognostic value of baseline prostate‐specific membrane antigen‐ligand positron emission tomography/computed tomography (PSMA‐PET/CT) in high‐risk, nonmetastatic PCa patients who received neoadjuvant hormonal or chemohormonal treatment followed by radical prostatectomy (RP).MethodsWe performed retrospective analyses of 70 patients with high‐risk, nonmetastatic PCa confirmed by biopsy between 2018 and 2021. All patients underwent neoadjuvant therapy followed by RP and pelvic lymph node dissection (PLND); PSMA‐PET/CT was performed before initiation of neoadjuvant therapy. Acquired image information and clinical characteristics/outcomes were examined for possible associations.ResultsAmong 70 high‐risk PCa patients, median age was 69 years old and median prostate specific antigen (PSA) at presentation was 58.5 ng/mL. Thirty (42.9%) patients had uptake of the PSMA tracer only in the primary PCa lesions and 40 (57.1%) patients had PSMA‐positive lesions in regional or distant sites. Sixteen (32%) localized PCa patients defined by pre‐PET magnetic resonance imaging were found to have locally advanced PCa based on PSMA‐PET/CT. Fifteen (30%) localized PCa patients and 7 (35%) locally advanced PCa patients were upstaged to metastatic PCa. The sensitivity and specificity of PSMA‑PET/CT for the detection of lymph node involvement were 90.9% and 69.5%, respectively, with a positive prediction value of 35.7% and negative prediction value of 97.6%. The diagnostic accuracy was 72.9%. Univariate analysis showed upstaging, tumor stage, and metastasis location based on PSMA‑PET/CT are predictors to PSA persistence after surgery, while multivariate logistic regression analysis showed only the tumor stage based on PSMA‐PET/CT remained an independent predictor of the outcome.ConclusionsThis study further highlights the accuracy and necessity of PSMA‐PET/CT in newly diagnosed, high‐risk, nonmetastatic PCa patients.