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?

Neurovascular Structure-adjacent Frozen-section Examination (NeuroSAFE) During Radical Prostatectomy: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

A standardized intraoperative frozen section analysis of the prostate resection margin adjacent to the neurovascular bundle according to the NeuroSAFE technique is performed to maximize nerve sparing during radical prostatectomy (RP) for prostate cancer (PCa). The aim of this review was to analyze oncological and functional outcomes of NeuroSAFE.

METHODS

A systematic search of the Medline, Embase, and Web of Science databases until July 2024 was performed. Studies were eligible if these included men undergoing RP with NeuroSAFE for PCa, and reported on oncological and/or functional outcomes. A cumulative analysis with random-effect models for oncological outcomes was conducted using Review Manager software, together with a narrative analysis of the procedure and functional outcomes.

KEY FINDINGS AND LIMITATIONS

We analyzed 14 studies with nine distinct patient populations; 7505 out of 15 446 patients underwent NeuroSAFE. The number of nerve-sparing procedures was higher for patients with NeuroSAFE than for controls in all studies. Cumulative analyses showed a statistically significantly lower risk of positive surgical margins (PSMs) in favor of NeuroSAFE (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.51-0.91, I2 = 79%) and no difference in 2-yr biochemical recurrence (BCR; OR 0.79, 95% CI 0.53-1.18, I2 = 63%). All studies with control groups showed higher potency rates in the NeuroSAFE group; none reported significant difference in continence rates. Adverse events were scarce. Limitations of the studies include a lack of randomization resulting in a selection bias; the overall risk of bias judgment ranged from low to serious.

CONCLUSIONS AND CLINICAL IMPLICATIONS

We present the first systematic review on NeuroSAFE during RP. The level of evidence is weak. The increased rate of nerve-sparing surgery, reduced PSMs, similar BCR, and low adverse event rates imply that NeuroSAFE is an oncologically safe technique. NeuroSAFE seems to improve functional outcomes, especially potency, but results of randomized trials are awaited.

PATIENT SUMMARY

We know that for patients with prostate cancer who undergo an operation to remove the prostate, sparing the nerve bundles next to each side of the prostate improves continence and erectile function. In this literature review, we evaluated a technique (NeuroSAFE) that aids surgeons in deciding whether they can spare these nerve bundles safely while still operating radically, for example, remove all cancer. We found that the technique is oncologically safe. Furthermore, the impact on potency appears promising but needs further study.

Centralized prostatectomy with intraoperative NeuroSAFE margin assessment improves surgical margin control

AIMS

To investigate the surgical margin status in patients with prostate cancer who underwent robot-assisted radical prostatectomy (RARP) with intraoperative neurovascular structure-adjacent frozen-section analysis (NeuroSAFE) and evaluate differences compared to patients who underwent radical prostatectomy without NeuroSAFE.

PATIENTS AND METHODS

Between September 2018 and January 2021, 962 patients underwent centralized RARP with NeuroSAFE. A secondary resection was performed in case of a positive surgical margin (PSM) on intraoperative frozen section (IFS) analysis to convert a PSM into a negative surgical margin (NSM). A retrospective cohort consisted of 835 patients who had undergone radical prostatectomy in a tertiary centre without NeuroSAFE between January 2000 and December 2017. We performed multivariable logistic regression to evaluate differences in risk of PSM between cohorts after controlling for clinicopathological variables.

RESULTS

Patients operated with NeuroSAFE in the centralized clinic had 29% PSM at a definitive pathological RP examination. The median cumulative length of definitive PSM was 1.1 mm (interquartile range: 0.4-3.8). Among 275 men with PSM, 136 (49%) had a cumulative length ≤1 mm and 198 (72%) ≤3 mm. After controlling for PSA, Grade group, cribriform pattern, pT-stage, and pN-stage, patients treated in the centralized clinic with NeuroSAFE had significantly lower odds on PSM (odds ratio [OR]: 0.70, 95% confidence interval [CI]: 0.56-0.88; P = 0.002), PSM length >1 mm (OR: 0.14, 95% CI: 0.09-0.22; P < 0.001), and >3 mm (OR: 0.21, 95% CI: 0.14-0.30; P < 0.001).

CONCLUSION

This study provides a detailed overview of surgical margin status in a centralized RP NeuroSAFE cohort. Centralization with NeuroSAFE was associated with lower PSM rates and significantly shorter PSM cumulative lengths, indicating improved control of surgical margin status.

Intraoperative margin assessment during radical prostatectomy: is microscopy frozen in time or ready for digital defrost?

Intraoperative frozen section (IFS) is used with the intention to improve functional and oncological outcomes for patients undergoing radical prostatectomy (RP). High resource requirements of IFS techniques such as NeuroSAFE may preclude widespread adoption, even if there are benefits to patients. Recent advances in fresh-tissue microscopic digital imaging technologies may offer an attractive alternative, and there is a growing body of evidence regarding these technologies. In this narrative review, we discuss some of the familiar limitations of IFS and compare these to the attractive counterpoints of modern digital imaging technologies such as the speed and ease of image generation, the locality of equipment within (or near) the operating room, the ability to maintain tissue integrity, and digital transfer of images. Confocal laser microscopy (CLM) is the modality most frequently reported in the literature for margin assessment during RP. We discuss several imitations and obstacles to widespread dissemination of digital imaging technologies. Among these, we consider how the 'en-face' margin perspective will challenge urologists and pathologists to understand afresh the meaning of positive margin significance. As a part of this, discussions on how to describe, categorize, react to, and evaluate these technologies are needed to improve patient outcomes. Limitations of this review include its narrative structure and that the evidence base in this field is relatively immature but developing at pace.

Impact of frozen section on long-term outcomes in robot-assisted laparoscopic prostatectomy

OBJECTIVES

To compare 1-year functional and 5-year oncological outcomes of men undergoing robot-assisted laparoscopic prostatectomy (RALP) with neurovascular structure-adjacent frozen-section examination (NeuroSAFE) with those in men undergoing RALP without NeuroSAFE (standard of care [SOC]).

SUBJECTS AND METHODS

Men undergoing RALP in our centre between 1 January 2009 and 30 June 2018 were enrolled from a prospectively maintained database. Patients were excluded if they had undergone preoperative therapy or postoperative adjuvant therapy or were enrolled in clinical trials. Patients were grouped based on use of NeuroSAFE. Follow-up was censored at 5 years. The primary outcome was difference in time to biochemical recurrence (BCR) on multivariable analysis, defined as prostate-specific antigen (PSA) >0.2 ng/L on two consecutive measurements. Secondary outcomes were difference in 1-year erectile dysfunction and incontinence.

RESULTS

In the enrolment period, 1199 consecutive men underwent RALP, of whom 1140 were eligible, including 317 with NeuroSAFE and 823 with SOC. The median PSA follow-up was 60 months in both groups. Rates of 5-year BCR were similar on Kaplan-Meier survival curve analysis (11% vs 11%; P = 0.9), as was time to BCR on multivariable Cox proportional hazards modelling (hazard ratio 1.2; P = 0.6). Compared with the SOC group at 1 year, the NeuroSAFE group had similar unadjusted rates of incontinence (5.1% vs 7.7%) and lower unadjusted impotence (57% vs 80%). On multivariable analysis, NeuroSAFE patients had equivalent risk of incontinence (odds ratio [OR] 0.59, 95% CI 0.17-1.6; P = 0.4) but significantly reduced risk of erectile dysfunction (OR 0.37, 95% CI 0.22-0.60; P < 0.001).

CONCLUSIONS

For men undergoing RALP, compared with SOC, NeuroSAFE patients had equivalent time to BCR and risk of 1-year incontinence, and significantly lower risk of 1-year erectile dysfunction.

Neurovascular structure-adjacent frozen-section examination (NeuroSAFE) during robot-assisted radical prostatectomy: a systematic review and meta-analysis of comparative studies

BACKGROUND

To compare surgical, pathological, and functional outcomes of patients undergoing NeuroSAFE-guided RARP vs. RARP alone.

METHODS

In February 2024, a literature search and assessment was conducted through PubMed®, Scopus®, and Web of Science™, to retrieve data of men with PCa (P) undergoing RARP with NeuroSAFE (I) versus RARP without NeuroSAFE (C) to evaluate surgical, pathological, oncological, and functional outcomes (O), across retrospective and/or prospective comparative studies (Studies). Surgical (operative time [OT], number of nerve-sparing [NS] RARP, number of secondary resections after NeuroSAFE), pathological (PSM), oncological (biochemical recurrence [BCR]), and functional (postoperative continence and sexual function recovery) outcomes were analyzed, using weighted mean difference (WMD) for continuous variables and odd ratio (OR) for dichotomous variables.

RESULTS

Overall, seven studies met the inclusion criteria (one randomized clinical trial, one prospective non-randomized trial and five retrospective studies) and were eligible for SR and MA. A total of 4,207 patients were included in the MA, with 2247 patients (53%) undergoing RARP with the addition of NeuroSAFE, and 1 960 (47%) receiving RARP alone. The addition of NeuroSAFE enhanced the likelihood of receiving a nerve-sparing (NS) RARP (OR 5.49, 95% CI 2.48-12.12, I2 = 72%). In the NeuroSAFE cohort, a statistically significant reduction in the likelihood of PSM at final pathology (OR 0.55, 95% CI 0.39-0.79, I2 = 73%) was observed. Similarly, a reduced likelihood of BCR favoring the NeuroSAFE was obtained (OR 0.47, 95% CI 0.35-0.62, I2 = 0%). At 12-month postoperatively, NeuroSAFE led to a significantly higher likelihood of being pad-free (OR 2.01, 95% CI 1.25-3.25, I2 = 0%), and of erectile function recovery (OR 3.50, 95% CI 2.34-5.23, I2 = 0%).

CONCLUSION

Available evidence suggests that NeuroSAFE might represent a histologically based approach to NVB preservation, broadening the indications of NS RARP, reducing the likelihood of PSM and subsequent BCR. In addition, it might translate into better functional postoperative outcomes. However, the current body of evidence is mostly derived from non-randomized studies with a high risk of bias.

Novel nerve-sparing robot-assisted radical prostatectomy with endopelvic fascia preservation and long-term outcomes for a single surgeon

Although novel techniques for avoiding incontinence during robot-assisted radical prostatectomy have been developed, long-term oncological outcomes are unknown. The objective of this study was to determine the long-term oncological outcomes and functional outcomes of novel nerve-sparing robot-assisted radical prostatectomy with endopelvic fascia preservation for a single surgeon. Data from 100 patients who underwent structure-preserving prostatectomies performed by a single surgeon were retrospectively analyzed. The median console time was 123 min. Bilateral nerve-sparing was performed in 43% of patients underwent, and 57% underwent unilateral nerve-sparing surgery. Most patients (96%) reached complete pad-zero urinary continence by one year after surgery. Satisfactory erectile function was achieved in 97% of patients who underwent bilateral nerve-sparing surgery, and 80% of patients who underwent unilateral nerve-sparing surgery. The surgical margin was positive for 25% of patients, and the biochemical recurrence-free rate at 5 years was 77%. The cancer-specific survival rate was 100% during the median follow-up period of 4.5 years. Clavien-Dindo grade III complications occurred in 1% of cases. The outcomes for novel nerve-sparing robot-assisted radical prostatectomy with endopelvic fascia preservation were similar to previously reported oncological outcomes, with satisfactory functional outcomes. This operative method may be useful for patients who are eligible for nerve-sparing surgery.