PD10-02 USING THE NEGATIVE PREDICTIVE VALUE AND SUVMAX OF PSMA PET/CT FOR AVOIDING PELVIC LYMPH NODE DISSECTION WITH RADICAL PROSTATECTOMY

Abstract

You have accessJournal of UrologyCME1 Apr 2023PD10-02 USING THE NEGATIVE PREDICTIVE VALUE AND SUVMAX OF PSMA PET/CT FOR AVOIDING PELVIC LYMPH NODE DISSECTION WITH RADICAL PROSTATECTOMY Amandeep Arora, Archi Agarwal, Mahendra Pal, Ganesh Bakshi, Santosh Menon, Gujela Ajit, and Gagan Prakash Amandeep AroraAmandeep Arora More articles by this author , Archi AgarwalArchi Agarwal More articles by this author , Mahendra PalMahendra Pal More articles by this author , Ganesh BakshiGanesh Bakshi More articles by this author , Santosh MenonSantosh Menon More articles by this author , Gujela AjitGujela Ajit More articles by this author , and Gagan PrakashGagan Prakash More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003250.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The prostate-specific membrane antigen positron-emission-tomography (PSMA-PET) scan is increasingly being utilized for staging prostate cancer (PCa). Here, we sought to evaluate the accuracy of the PSMA-PET scan with the aim of identifying patients who could be spared a pelvic lymph node dissection (PLND) at the time of radical prostatectomy (RP) based on the results of the PSMA-PET scan. METHODS: We retrospectively reviewed records of patients who underwent a PSMA-PET scan followed by an RP with extended PLND (external iliac, obturator and common iliac nodes) at our tertiary cancer care centre from Aug 2015 - September 2022. Patients were classified as clinically node negative or positive (cN0 or cN+) based on the PSMA PET scan. The nodal status in the PSMA-PET scan was compared with the final histopathology of the PLND (pN0 or pN+). RESULTS: A total of 205 patients were included and were stratified as follows based on MRI and PSMA-PET scans: 6 (2.9%) low-risk, 49 (23.9%) intermediate-risk, 46 (22.4%) high-risk localized, 89 (43.4%) locally-advanced node-negative and 15 (7.3%) node-positive patients. The sensitivity, specificity, positive predictive value, and negative predictive value of the PSMA PET scan for nodal status were 37.5%, 98.2%, 80% and 89.4% respectively. The NPV was 89.4%, 93.8%, 87% and 86.6% for overall, intermediate-risk, high-risk localized and locally-advanced node-negative patients respectively. The median SUVmax of the primary prostate lesion in patients who were true negatives for nodes, as identified by the PSMA-PET scan, was significantly lower (12.8 vs 26.4, p<0.001) than that in patients who were false negative (cN0 on PSMA but pN+ in final pathology). Of the 190 cN0 patients, 20 had a false negative PSMA PET scan. Three of the 49 intermediate-risk patients had a false negative PSMA PET scan for nodes; the SUVmax scores of their prostate lesions were 26.59, 40.06 and 54.55 which were much higher than the median SUVmax score (12.8) in patients with a true negative scan. For the 135 high-risk cN0 patients, the 17 false negative patients had a median SUVmax of 24.37 compared to those with a true negative scan (13.57), p<0.001. CONCLUSIONS: The high NPV of PSMA-PET scan coupled with the SUVmax of the primary prostatic lesion can help avoid a PLND in intermediate and high-risk patients with a ‘negative’ PSMA-PET scan. The results can be considered as hypothesis generating and indicate the use of PSMA as a biomarker for predicting nodal disease. Further larger studies can help determine the ideal cut-off values for the SUVmax of the primary lesion. Source of Funding: No © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e326 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Amandeep Arora More articles by this author Archi Agarwal More articles by this author Mahendra Pal More articles by this author Ganesh Bakshi More articles by this author Santosh Menon More articles by this author Gujela Ajit More articles by this author Gagan Prakash More articles by this author Expand All Advertisement PDF downloadLoading ...