Implementation of Intraoperative Frozen Section During Radical Prostatectomy: Short-term Results from a German Tertiary-care Center

Abstract

Background: Neurovascular bundle (NVB) preservation (NVBP) and surgical margin status are the main intraoperative factors influencing functional and oncologic outcomes in patients with prostate cancer undergoing radical prostatectomy (RP).

Objective: To test the impact of implementing the intraoperative frozen section technique (IFST) during NVBP on the frequency of NVB procedures and its effect on positive surgical margins (PSMs).

Design, setting, and participants: We relied on an institutional tertiary-care center database to identify patients who underwent RP (January 2014-October 2018). Until October 2017, decision for NVBP was taken based on preoperative magnetic resonance imaging, clinical characteristics, and nomograms, without the IFST. After November 2017, all patients received bilateral NVBP with the IFST, to check for a PSM in the area of the NVB. If a PSM occurred, a secondary resection of the respective NVB was performed.

Outcome measurements and statistical analysis: PSM and NVB procedures were assessed. Subgroup analyses focused on pathologic tumor stages.

Results and limitations: Overall, 346 patients were identified. Of these patients, 54.9% (n=190) versus 45.1% (n=156) underwent RP without versus with the IFST. By using the IFST during NVBP, the PSM decreased from 29.5% to 15.4% (p=0.003) in the entire cohort (14.6% vs 8.6% in pT2; 47.1% vs 29.4% in pT3). Conversely, NVBP increased from 55.3% to 95.5% (p<0.001) in the entire cohort (68.9% vs 99.0% in pT2; 39.1% vs 88.2% in pT3). In multivariable logistic regressions, IFST use was an independent predictor of PSMs (odds ratio [OR]: 0.54, 95% confidence interval [CI]: 0.30-0.98; p=0.047) and NVBP (OR: 5.60, 95% CI: 3.10-10.51; p<0.001) after controlling for patient and tumor characteristics.

Conclusions: Implementation of the IFST during NVBP resulted in more frequent NVBP and was associated with a lower PSM, compared with RP without the IFST. Therefore, the IFST should be performed, if available.

Patient summary: The intraoperative frozen section technique (IFST) during preservation of neurovascular bundles (NVBP) should be offered to patients who undergo radical prostatectomy. The IFST can reduce positive margin rates and increase the rate of NVBP.

Keywords: Frozen section; Nerve sparing; Positive margins; Prostatectomy.