Intraoperative Frozen Section via Neurosafe During Robotic Radical Prostatectomy in the Era of Preoperative Risk Stratifications and Primary Staging With mpMRI and PSMA-PET CT: Is There a Perfect Candidate?

Background: We aimed to analyze the effect of preoperative risk assessment including Ga-68 PSMA PET and multiparametric magnetic resonance imaging (mpMRI) on nerve sparing practices, positive surgical margin (PSM) rates and oncological outcomes based on a comparison between patients underwent RARP with and without Neurosafe (NS).

Methods: Patients underwent RARP with NS (RARP-NS) or without (RARP-only) NS retrospectively evaluated. Suspicion for extracapsular extension on mpMRI and/or Ga-68 PSMA PET was recorded as i(imaging)T3. NS was performed according to the Martini-Klinik technique. PSM at preserved bundle side were called PSM at region of interest (ROI) while the others were elsewhere.

Results: A total of 208 patients (90 in RARP-NS, 118 in RARP-only groups) were included. Preoperatively the RARP-only group showed significantly higher mean PSA (p = .01) and PIRADS 5 (p = .002) findings and had more D'Amico high risk (DAHR) patients (p = .08). The overall PSM rates for pT2 versus pT3 disease were 7.5% versus 21.6 and 15.6% versus 55% in RARP-NS and RARP-only groups, respectively. NS resulted in more bilaterally preserved bundles (81.1% vs. 66.3%) and less PSM at the ROI (3.3% vs. 23.4%) than RARP-only group. NS outperformed RARP-only in all clinical settings had its highest differential benefit in more bilateral nerve sparing and less PSM at ROI in patients with both DAHR and iT3 disease. BCR rates were 2.2% and 2.5% for RARP-NS and RARP only groups, respectively (p = .4). One patient in RARP-NS and 9 in RARP-only groups had PSA persistence (p = .02).

Conclusion: RARP-NS led to more preserved bundles with less PSM. It was especially useful in DAHR patients with preoperative extracapsular extension suspicion in imaging simultaneously.