Utility of 18F-DCFPyL PET for local staging for high or very high risk prostate cancer for patients undergoing radical prostatectomy.

Objective: PSMA PET offers the potential for improved local staging prior to radical prostatectomy (RP). We evaluated PSMA PET versus mpMRI for local and nodal staging for patients with localized NCCN high or very high risk prostate cancer undergoing RP. Methods: A prospective single center pilot study was conducted from 9/2018 to 6/2022. Patients underwent both mpMRI and 18F-DCFPyL PSMA PET with limited MRI sequences, followed by RP with pelvic lymphadenectomy. Patient and side-specific performance of mpMRI and PSMA PET were compared to RP histopathological standard of truth for extraprostatic extension (EPE), seminal vesicle invasion (SVI), and lymph node involvement (LNI). Results: At RP, 79% (38/48) had EPE, 31% had SVI, and 31% had LNI. At the patient level for EPE, PSMA PET had similar sensitivity (65.8% vs. 84.2%, respectively, P = 0.07) but higher specificity (80% vs. 40%, P = 0.045) compared to mpMRI, respectively. For SVI, PSMA PET had lower sensitivity (62.5% vs. 87.5%, P = 0.046) and similar specificity (87.5% vs. 90.6%, P = 0.56). For side-specific LNI, PSMA PET had higher sensitivity (50% vs. 25%, P = 0.03) and similar specificity (96.1% vs. 94.7%, P = 0.71) compared to mpMRI. Conclusions: PSMA PET offers higher specificity for EPE and higher sensitivity for LNI compared to mpMRI. PSMA PET may improve overall surgical planning, and may be combined with diagnostic mpMRI and clinicopathological variables through nomograms to further predict EPE, SVI, or LNI.

Background: NCT03392181 https://clinicaltrials.gov/study/NCT03392181 .