Negative PSMA PET can be used to avoid unnecessary pelvic lymph node dissection in intermediate risk prostate cancer

Abstract

BackgroundProstate-specific membrane antigen (PSMA) positron emission tomography (PET) has a high negative predictive value (NPV) in determining lymph node invasion (LNI) in men with intermediate-risk disease undergoing radical prostatectomy (RP) and pelvic lymph node dissection (PLND). We hypothesized that PSMA PET may be used to reduce the number of unnecessary PLND procedures performed.ObjectiveTo assess BCR-free survival of intermediate risk prostate cancer patients with a negative PSMA PET who underwent PLND vs. no PLND.Design, setting, and participantsWithin a high-volume center database, we identified patients with Grade Group 2-3 and PSA <= 20 ng/ml who had a negative PSMA PET prior to RP between 2016 and 2021.Outcome measurements and statistical analysisKaplan-Meier analyses were used to compare BCR-free survival between patients with and without PLND.Results and limitationsOverall, 371 patients were identified. Of those, 333 (90%) underwent RP with PLND, while 38 (10%) had no PLND during RP. Median number of removed lymph nodes in patients with PLND was 16. The NPV of PSMA PET for LNI detection was 90.1%. Median follow-up was 36 months. The median preoperative PSA was 7.8 ng/ml. 59% had biopsy Grade Group 2 and 41% had biopsy Grade Group 3, respectively. BCR-free survival at 36 months after prostatectomy was 78.7% vs. 76.7% (p = 0.8) for patients with vs. without PLND. Main limitation is the absence of long-term oncologic outcomes.ConclusionsIn intermediate risk prostate cancer patients, a PLND may be avoided in the presence of a negative PSMA PET.