Objectives
To investigate the impact of intraoperative neurovascular structure-adjacent frozen-section examination (NeuroSAFE) on nerve-sparing surgery (NSS) and oncological outcome in a large radical prostatectomy (RP) cohort.
Patients and methods
Between January 2016 and December 2020, 1756 prostate cancer patients underwent robot-assisted RP, of whom 959 (55%) with NeuroSAFE and 797 (45%) without (control cohort). In case the NeuroSAFE showed tumour in the margin, a secondary resection was performed. The effect of NeuroSAFE on NSS and positive surgical margin (PSM) status was analysed using logistic regression. Cox regression was used to identify predictors of biochemical recurrence-free survival (BCRFS).
Results and limitations
Men in the NeuroSAFE cohort had higher tumour grade (p<0.001) and clinical stage (p<0.001) than in the control cohort. NeuroSAFE enabled more frequent NSS in both pT2 (93% versus 76%; p<0.001) and pT3 disease (83% versus 55%; p<0.001). In adjusted analysis, NeuroSAFE resulted in more frequent uni- (odds ratio (OR) 3.90; 95% confidence interval (CI) 2.90-5.30; p<0.001) and bilateral (OR 5.22; 95%CI 3.90-6.98; p<0.001) NSS. While the PSM rate decreased from 51% to 42% in pT3 stage (p=0.031), NeuroSAFE was not an independent predictor for PSM status (OR 0.85; 95% CI 0.68-1.06; p=0.2) in the entire cohort. Patients who underwent NeuroSAFE had improved BCRFS (Hazard Ratio 0.62; 95% CI 0.45-0.84; p=0.002). This study is limited by its comparison with a historical cohort and lack of functional outcomes.
Conclusions
NeuroSAFE enables more unilateral and bilateral NSS without negatively affecting surgical margin status and biochemical recurrence. This validation study provides a comprehensive overview on the implementation, evaluation and intraoperative decision-making of NeuroSAFE in clinical practise.