PD22-05 IS PRE OPERATIVE PSMA (PROSTATE SPECIFIC MEMBRANE ANTIGEN) PET/CT A RELIABLE PREDICTOR OF PELVIC LYMPH NODE METASTASIS IN INTERMEDIATE AND HIGH RISK LOCALISED PROSTATE CANCER:A MULTI CENTRE RETROSPECTIVE ANALYSIS

Abstract

You have accessJournal of UrologyCME1 Apr 2023PD22-05 IS PRE OPERATIVE PSMA (PROSTATE SPECIFIC MEMBRANE ANTIGEN) PET/CT A RELIABLE PREDICTOR OF PELVIC LYMPH NODE METASTASIS IN INTERMEDIATE AND HIGH RISK LOCALISED PROSTATE CANCER:A MULTI CENTRE RETROSPECTIVE ANALYSIS Kishore Ta, Dinesh Cherian, Deepak Kaddu, Bikramjit Sodhi, Ravi Chandran, and Ginil Kumar Pooleri Kishore TaKishore Ta More articles by this author , Dinesh CherianDinesh Cherian More articles by this author , Deepak KadduDeepak Kaddu More articles by this author , Bikramjit SodhiBikramjit Sodhi More articles by this author , Ravi ChandranRavi Chandran More articles by this author , and Ginil Kumar PooleriGinil Kumar Pooleri More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003295.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Functional imaging techniques have been incorporated into conventional anatomical imaging to help improve identification of metastasis in normal sized nodes The primary objective of this study was to retrospectively analyse the percentage of patients “negative for metastasis” on 68Ga PSMA PETCT that translated to absent pelvic node metastasis on histopathology (Negative predictive value-NPV). The secondary objective was to analyse if pathological T stage and biopsy ISUP grades influenced the NPV of the PSMA PET CT. METHODS: A total of 217 biopsy-proven, treatment-naive, intermediate and high-risk (D’Amico classification) localised prostate cancer patients from two institutions were included in the study. All the patients had undergone a pre operative PSMA PET/ CT assessment of their pelvic lymph nodes and the patients “negative for metastasis” underwent Robotic assisted radical prostatectomy with extended pelvic lymph node dissection-ePLND. RESULTS: 49/217 patients had positive nodes despite PSMA PET/CT showing no evidence of lymph node metastasis,of which 27(55.10%) of them were obese. Thus the negative predictive value(NPV) was 77.42%. The NPV of PSMA PET CT in patients with intermediate risk prostate cancer was 86.9% compared to 71.43% in patients with high risk prostate cancer. As the ISUP biopsy grade increased the NPV decreased from 94.12% in ISUP 1 to 44.83%(p<0.0001) in ISUP 5.On retrospective analysis, all intermediate risk patients with a <pT3 stage had a 100% NPV on the PSMA PET/CT while high risk patients with a <pT3 had a NPV of 91.6%.The secondary objective was to analyse if T stage influenced the NPV .In comparison to organ confined disease(pT2) the NPV of those with disease extending beyond the prostate(pT3) was significantly lower, (80.36% vs100%) in intermediate risk and (66.97% vs 91.6%)in high risk patients. CONCLUSIONS: PSMA PET CT cannot replace e PLND with respect to accurate preoperative lymph nodal staging in intermediate and high risk prostate cancer since the NPV is below 95% (86.9%,71.43% respectively. PSMA PET CT is also not accurate with the T staging because pre operative T2 was upstaged to pT3 in 66.6 % of intermediate risk and 81.9% of high risk patients.Thus preoperative PSMA PET CT is not reliable for accurate T and N staging and e PLND should be the standard of care for precise staging in intermediate and high risk localized prostate cancer. Source of Funding: Self funded study © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e666 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kishore Ta More articles by this author Dinesh Cherian More articles by this author Deepak Kaddu More articles by this author Bikramjit Sodhi More articles by this author Ravi Chandran More articles by this author Ginil Kumar Pooleri More articles by this author Expand All Advertisement PDF downloadLoading ...