Intraoperative assessment and reporting of radical prostatectomy specimens to guide nerve-sparing surgery in prostate cancer patients (NeuroSAFE)

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.

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.

Neurovascular Structure-Adjacent Frozen-Section Examination (NeuroSAFE) Technique of Nerve-Sparing Robot-Assisted Radical Prostatectomy (RARP) in Indian Scenario: Technique, Feasibility, and Early Outcomes

Potency and urinary continence are adversely affected post-prostatectomy. The primary objective is oncological safety by ensuring negative surgical margins (NSM) and best functional recovery through nerve preservation in appropriate patients. NeuroSAFE technique of intra-operative frozen-section (IFS) analysis was devised for comprehensive assessment of surgical margins adjacent to the neurovascular tissue surface of the prostate. We analyzed our initial experience with this technique. Five NS-RARPs were performed utilizing the NeuroSAFE technique between October 2021 and February 2022. Patient demographics, disease stage, operative console time, post-operative complications, final histopathology, biochemical recurrence (BCR), erectile function, and urinary continence were recorded. The mean age of patients was 59.2 ± 1.3 years. All had clinically organ-confined disease with ISUP grade ≤ 3. The mean operative time of NS-RARP with NeuroSAFE was 240 ± 21 min and average NeuroSAFE time was 45 ± 3.8 min. All patients had NSM on IFS. No patient had Clavien-Dindo grade > 1 complications. Margins were negative on final histopathology. No patient had BCR at 6 and 12 weeks. Three patients were able to have sexual intercourse and only one patient required single precaution pad at 12 weeks. NeuroSAFE is feasible and can ensure intra-operative oncological safety of the NS procedure. Moreover, it gives the opportunity to convert positive surgical margin to prognostically favorable NSM by secondary resection. Our initial experience which is the first in India is encouraging with favorable functional outcomes. Large prospective studies and longer follow-up are required specially to evaluate the oncological benefit.

Predicting contralateral extraprostatic extension in unilateral high-risk prostate cancer: a multicentric external validation study

PURPOSE

Accurate prediction of extraprostatic extension (EPE) is crucial for decision-making in radical prostatectomy (RP), especially in nerve-sparing strategies. Martini et al. introduced a three-tier algorithm for predicting contralateral EPE in unilateral high-risk prostate cancer (PCa). The aim of the study is to externally validate this model in a multicentric European cohort of patients.

METHODS

The data from 208 unilateral high-risk PCa patients diagnosed through magnetic resonance imaging (MRI)-targeted and systematic biopsies, treated with RP between January 2016 and November 2021 at eight referral centers were collected. The evaluation of model performance involved measures such as discrimination (AUC), calibration, and decision-curve analysis (DCA) following TRIPOD guidelines. In addition, a comparison was made with two established multivariable logistic regression models predicting the risk of side specific EPE for assessment purposes.

RESULTS

Overall, 38%, 48%, and 14% of patients were categorized as low, intermediate, and high-risk groups according to Martini et al.'s model, respectively. At final pathology, EPE on the contralateral prostatic lobe occurred in 6.3%, 12%, and 34% of patients in the respective risk groups. The algorithm demonstrated acceptable discrimination (AUC 0.68), comparable to other multivariable logistic regression models (p = 0.3), adequate calibration and the highest net benefit in DCA. The limitations include the modest sample size, retrospective design, and lack of central revision.

CONCLUSION

Our findings endorse the algorithm's commendable performance, supporting its utility in guiding treatment decisions for unilateral high-risk PCa patients.

Urinary Incontinence and Sexual Function After the Introduction of NeuroSAFE in Radical Prostatectomy for Prostate Cancer

BACKGROUND

Nerve-sparing (NS) radical prostatectomy (RP) results in better functional outcomes. Intraoperative neurovascular structure-adjacent frozen section examination (NeuroSAFE) significantly increases the frequency of NS surgery. The effect of NeuroSAFE on postoperative erectile function (EF) and continence is not yet clear.

OBJECTIVE

To describe EF and continence outcomes for men undergoing RP with the NeuroSAFE technique.

DESIGN, SETTING, AND PARTICIPANTS

Between September 2018 and February 2021, 1034 men underwent robot-assisted RP. Data for patient-reported outcomes were collected via validated questionnaires.

INTERVENTION

NeuroSAFE technique for RP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Continence was assessed using the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) or Expanded Prostate Cancer Index Composite short form (EPIC-26) and defined as use of 0-1 pads/d. EF was evaluated using EPIC-26 or the International Index of Erectile Function short form (IIEF-5), with data converted according to the Vertosick method and categorized. Descriptive statistics were used to asses and describe tumor characteristics and continence and EF outcomes.

RESULTS AND LIMITATIONS

Of the 1034 men who underwent RP after introduction of the NeuroSAFE technique, 63% and 60% completed a preoperative and at least one postoperative questionnaire on continence and EF, respectively. Of the men who underwent unilateral or bilateral NS surgery, use of 0-1 pads/d was reported by 93% after 1 yr and 96% after 2 yr; the corresponding rates for men who underwent non-NS surgery were 86% and 78%. Overall, use of 0-1 pads/d was reported by 92% of the men at 1 yr and by 94% at 2 yr after RP. Men in the NS group had a good or intermediate Vertosick score after RP more often than the non-NS group. Overall, 44% of the men had a good or intermediate Vertosick score at 1 and 2 yr after RP.

CONCLUSIONS

After introduction of the NeuroSAFE technique, the continence rate was 92% at 1 yr and 94% at 2 yr after RP. The NS group had a greater percentage of men with an intermediate or good Vertosick score and a higher continence rate after RP in comparison to the non-NS group.

PATIENT SUMMARY

Our study shows that after introduction of the NeuroSAFE technique during removal of the prostate, the continence rate among patients was 92% at 1 year and 94% at 2 years after surgery. Some 44% of the men had a good or intermediate score for erectile function 1 and 2 years after surgery.

Biopsy prostate cancer perineural invasion and tumour load are associated with positive posterolateral margins at radical prostatectomy: implications for planning of nerve-sparing surgery

AIMS

Radical prostatectomy (RP) for prostate cancer is frequently complicated by erectile dysfunction and urinary incontinence. However, sparing of the nerve bundles adjacent to the posterolateral sides of the prostate reduces the number of complications at the risk of positive surgical margins. Preoperative selection of men eligible for safe, nerve-sparing surgery is therefore needed. Our aim was to identify pathological factors associated with positive posterolateral surgical margins in men undergoing bilateral nerve-sparing RP.

METHODS AND RESULTS

Prostate cancer patients undergoing RP with standardised intra-operative surgical margin assessment according to the NeuroSAFE technique were included. Preoperative biopsies were reviewed for grade group (GG), cribriform and/or intraductal carcinoma (CR/IDC), perineural invasion (PNI), cumulative tumour length and extraprostatic extension (EPE). Of 624 included patients, 573 (91.8%) received NeuroSAFE bilaterally and 51 (8.2%) unilaterally, resulting in a total of 1197 intraoperative posterolateral surgical margin assessments. Side-specific biopsy findings were correlated to ipsilateral NeuroSAFE outcome. Higher biopsy GG, CR/IDC, PNI, EPE, number of positive biopsies and cumulative tumour length were all associated with positive posterolateral margins. In multivariable bivariate logistic regression, ipsilateral PNI [odds ratio (OR) = 2.98, 95% confidence interval (CI) = 1.62-5.48; P < 0.001] and percentage of positive cores (OR = 1.18, 95% CI = 1.08-1.29; P < 0.001) were significant predictors for a positive posterolateral margin, while GG and CR/IDC were not.

CONCLUSIONS

Ipsilateral PNI and percentage of positive cores were significant predictors for a positive posterolateral surgical margin at RP. Biopsy PNI and tumour volume can therefore support clinical decision-making on the level of nerve-sparing surgery in prostate cancer patients.

Stimulated Raman histology, a novel method to allow for rapid pathologic examination of unprocessed, fresh prostate biopsies

INTRODUCTION

Delay between targeted prostate biopsy (PB) and pathologic diagnosis can lead to a concern of inadequate sampling and repeated biopsy. Stimulated Raman histology (SRH) is a novel microscopic technique allowing real-time, label-free, high-resolution microscopic images of unprocessed, unsectioned tissue. This technology holds potential to decrease the time for PB diagnosis from days to minutes. We evaluated the concordance of pathologist interpretation of PB SRH as compared with traditional hematoxylin and eosin (H&E) stained slides.

METHODS

Men undergoing prostatectomy were included in an IRB-approved prospective study. Ex vivo 18-gauge PB cores, taken from prostatectomy specimen, were scanned in an SRH microscope (NIO; Invenio Imaging) at 20 microns depth using two Raman shifts: 2845 and 2930 cm^-1 , to create SRH images. The cores were then processed as per normal pathologic protocols. Sixteen PB containing a mix of benign and malignant histology were used as an SRH training cohort for four genitourinary pathologists, who were then tested on a set of 32 PBs imaged by SRH and processed by traditional H&E. Sensitivity, specificity, accuracy, and concordance for prostate cancer (PCa) detection on SRH relative to H&E were assessed.

RESULTS

The mean pathologist accuracy for the identification of any PCa on PB SRH was 95.7%. In identifying any PCa or ISUP grade group 2-5 PCa, a pathologist was independently able to achieve good and very good concordance (κ: 0.769 and 0.845, respectively; p < 0.001). After individual assessment was completed a pathology consensus conference was held for the interpretation of the PB SRH; after the consensus conference the pathologists' concordance in identifying any PCa was also very good (κ: 0.925, p < 0.001; sensitivity 95.6%; specificity 100%).

CONCLUSION

SRH produces high-quality microscopic images that allow for accurate identification of PCa in real-time without need for sectioning or tissue processing. The pathologist performance improved through progressive training, showing that ultimately high accuracy can be obtained. Ongoing SRH evaluation in the diagnostic and treatment setting hold promise to reduce time to tissue diagnosis, while interpretation by convolutional neural network may further improve diagnostic characteristics and broaden use.

The NeuroSAFE frozen section technique during radical prostatectomy - Implementation and optimization of technical aspects in a routine pathology workflow

BACKGROUND AND AIMS

In prostate cancer patients, application of the NeuroSAFE frozen section technique during radical prostatectomy has been shown to increase the rate of nerve sparing surgery and to improve functional outcome for the patients. The aim of this study is to report on technical and organizational optimization opportunities of the procedure.

MATERIAL AND METHODS

All patients submitted to bilateral intraoperative frozen section from January 2018 until December 2020 (n = 452) were retrospectively analyzed and parameters such as turnaround time, staff situation in the laboratory and histologic properties of the tumors were assessed.

RESULTS

The median turnaround time per case was 40.3 ( ± 10.5) min. In 2020 the average time needed from accessioning to diagnosis was 38.1 min. Multivariate linear regression suggested that the number of technical assistants/cryotomes (46.1 min vs. 39.13 min; p < 0.001), the place of microscopic examination (43.0 min vs. 38.7 min; p < 0.001) and the presence of a positive margin (38.0 vs. 44.0 min; p < 0.001) were significant influential factors. The turnaround time was independent of the uropathological expertize of the consultant (39.84 min vs. 40.7 min; p = 0.09), the tumor grade (42.3 vs 39.8 min; p = 0.493) and the presence of extraprostatic extension (44.0 vs 39.8 min; p = 0.099).

CONCLUSION

The implementation of simple optimization measures in the workflow as well as structured training of all pathology staff involved in the examination leads to a significant increase in the efficiency of the examination while maintaining the same level of resources. The results could thus be a contribution to the broader application of the procedure.

NeuroSAFE in radical prostatectomy increases the rate of nerve-sparing surgery without affecting oncological outcome

OBJECTIVES

To investigate the impact of intra-operative neurovascular structure-adjacent frozen-section examination (NeuroSAFE) on the rate of 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%) underwent this with NeuroSAFE and 797 (45%) without (control cohort). In cases where 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

Patients in the NeuroSAFE cohort had a higher tumour grade (P < 0.001) and clinical stage (P < 0.001) than those in the control cohort. NeuroSAFE enabled more frequent NSS for both pT2 (93% vs 76%; P < 0.001) and pT3 disease (83% vs 55%; P < 0.001). In adjusted analysis, NeuroSAFE resulted in more frequent unilateral (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 patients with pT3 stage disease (P = 0.031), NeuroSAFE was not an independent predictor of PSM status (OR 0.85, 95% CI 0.68-1.06; P = 0.2) in the entire cohort. Patients who underwent NeuroSAFE had better BCRFS compared to the control cohort (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 of the implementation, evaluation and intra-operative decision making associated with NeuroSAFE in clinical practice.

NeuroSAFE PROOF: study protocol for a single-blinded, IDEAL stage 3, multi-centre, randomised controlled trial of NeuroSAFE robotic-assisted radical prostatectomy versus standard robotic-assisted radical prostatectomy in men with localized prostate cancer

BACKGROUND

Robotic radical prostatectomy (RARP) is a first-line curative treatment option for localized prostate cancer. Postoperative erectile dysfunction and urinary incontinence are common associated adverse side effects that can negatively impact patients' quality of life. Preserving the lateral neurovascular bundles (NS) during RARP improves functional outcomes. However, selecting men for NS may be difficult when there is concern about incurring in positive surgical margin (PSM) which in turn risks adverse oncological outcomes. The NeuroSAFE technique (intra-operative frozen section examination of the neurovascular structure adjacent prostate margin) can provide real-time pathological consult to promote optimal NS whilst avoiding PSM.

METHODS

NeuroSAFE PROOF is a single-blinded, multi-centre, randomised controlled trial (RCT) in which men are randomly allocated 1:1 to either NeuroSAFE RARP or standard RARP. Men electing for RARP as primary treatment, who are continent and have good baseline erectile function (EF), defined by International Index of Erectile Function (IIEF-5) score > 21, are eligible. NS in the intervention arm is guided by the NeuroSAFE technique. NS in the standard arm is based on standard of care, i.e. a pre-operative image-based planning meeting, patient-specific clinical information, and digital rectal examination. The primary outcome is assessment of EF at 12 months. The primary endpoint is the proportion of men who achieve IIEF-5 score ≥ 21. A sample size of 404 was calculated to give a power of 90% to detect a difference of 14% between groups based on a feasibility study. Oncological outcomes are continuously monitored by an independent Data Monitoring Committee. Key secondary outcomes include urinary continence at 3 months assessed by the international consultation on incontinence questionnaire, rate of biochemical recurrence, EF recovery at 24 months, and difference in quality of life.

DISCUSSION

NeuroSAFE PROOF is the first RCT of intra-operative frozen section during radical prostatectomy in the world. It is properly powered to evaluate a difference in the recovery of EF for men undergoing RARP assessed by patient-reported outcome measures. It will provide evidence to guide the use of the NeuroSAFE technique around the world.

TRIAL REGISTRATION

NCT03317990 (23 October 2017). Regional Ethics Committee; reference 17/LO/1978.

Cerenkov Luminescence Imaging in Prostate Cancer: Not the Only Light That Shines

Cerenkov luminescence imaging (CLI) is a novel imaging technology that might have the ability to assess surgical margins intraoperatively during prostatectomy using 68Ga-prostate-specific membrane antigen (68Ga-PSMA-11). This study evaluated the accuracy of CLI compared with histopathology and, as an exploratory objective, investigated the characteristics of the identified chemiluminescence signal. Methods: After intravenous injection of a mean 68Ga-PSMA-11 activity of 69 MBq intraoperatively, all excised specimens were imaged with CLI. Areas of increased signal were marked for histopathologic comparison and scored for the likelihood of being a positive surgical margin (PSM) using a 5-point Likert scale. In addition, the chemiluminescence signal was investigated in 3 radioactive and 3 nonradioactive specimens using CLI. Results: In 15 patients, the agreement between CLI and histopathology was 60%; this improved to 83% when including close surgical margins (≤1 mm). In 6 hot spots, CLI correctly identified PSMs on histopathology, located at the apex and mid prostate. In all 15 patients, an increased signal at the prostate base was observed, without the presence of the primary tumor in this area in 8 patients. This chemiluminescence signal was also observed in nonradioactive prostate specimens, with a half-life of 48 ± 11 min. The chemiluminescence hampered the visual interpretation of 4 PSMs at the base. Conclusion: CLI was able to correctly identify margin status, including close margins, in 83% of the cases. The presence of a diathermy-induced chemiluminescent signal hampered image interpretation, especially at the base of the prostate. In the current form, CLI is most applicable to detect PSMs and close margins in the apex and mid prostate.

Neurovascular structure-adjacent frozen-section examination robotic-assisted radical prostatectomy: outcomes from 500 consecutive cases in the UK

The purpose is to report the United Kingdom's largest single-centre experience of robotically assisted laparoscopic radical prostatectomies (RALP), using the neurovascular structure-adjacent frozen-section (NeuroSAFE) technique. We describe the utilisation and outcomes of this technique. This is a retrospective study from 2012 to 2019 on 520 patients undergoing NeuroSAFE RALP at our Institution. Our Institution's database was analysed for false-positive frozen-section (FS) margins as confirmed on paraffin histopathological analysis: functional outcomes of potency, continence, and biochemical recurrence (BCR). The median (range) of console time was 145 (90-300) min. In our cohort, positive FS was seen in 30.7% (160/520) of patients, with a confirmatory paraffin analysis in 91.8% of our patients' cohort (147/160). The neurovascular bundles (NVBs) that underwent secondary resection contained tumour in 26.8% (43/160) of the cases. Biochemical recurrence (BCR) was 6.7% (35/520), of which FS was positive in 40% (14/35) of those cases. There were insufficient evidence of a statistical association of urinary incontinence and positive surgical margin rates according to NS or NVB resection. NeuroSAFE enables intraoperative confirmation of the oncologic safety of a NS procedure. Patients with a positive FS on NeuroSAFE can be converted to a negative surgical margin (NSM) by ipsilateral wide resection. This spared 1 in 4 men from positive margins posterolaterally in our series. Limitations are the absence of a matched contemporary cohort of NS RALP without NeuroSAFE in our centre.

NeuroSAFE frozen section during robot-assisted radical prostatectomy: peri-operative and histopathological outcomes from the NeuroSAFE PROOF feasibility randomized controlled trial

OBJECTIVES

To report on the methods, peri-operative outcomes and histopathological concordance between frozen and final section from the NeuroSAFE PROOF feasibility study (NCT03317990).

PATIENTS AND METHODS

Between May 2018 and March 2019, 49 patients at two UK centres underwent robot-assisted radical prostatectomy (RARP). Twenty-five patient were randomized to NeuroSAFE RARP (intervention arm) and 24 to standard RARP (control arm). Frozen section was compared to final paraffin section margin assessment in the 25 patients in the NeuroSAFE arm. Operation timings and complications were collected prospectively in both arms.

RESULTS

Fifty neurovascular bundles (NVBs) from 25 patients in the NeuroSAFE arm were analysed. When analysed by each pathological section (n = 250, average five per side), we noted a sensitivity of 100%, a specificity of 99.2%, and an area under the curve (AUC) of 0.994 (95% confidence interval [CI] 0.985 to 1; P ≤0.001). On an NVB basis (n = 50), sensitivity was 100%, specificity was 92.7%, and the AUC was 0.963 (95% CI 0.914 to 1; P ≤0.001). NeuroSAFE RARP lasted a mean of 3 h 16 min (knife to skin to off table, 95% CI 3 h 2 min-3 h 30 min) compared to 2 h 4 min (95% CI 2 h 2 min-2 h 25 min; P ≤0.001) for standard RARP. There was no morbidity associated with the additional length of operating time on in the NeuroSAFE arm.

CONCLUSION

This feasibility study demonstrates the safety, reproducibility and excellent histopathological concordance of the NeuroSAFE technique in the NeuroSAFE PROOF trial. Although the technique increases the duration of RARP, this does not cause short-term harm. Confirmation of feasibility has led to the opening of the fully powered NeuroSAFE PROOF randomized controlled trial, which is currently under way at four sites in the UK.

Intraoperative assessment and reporting of radical prostatectomy specimens to guide nerve-sparing surgery in prostate cancer patients (NeuroSAFE)

Aims

Radical prostatectomy for prostate cancer is frequently complicated by urinary incontinence and erectile dysfunction. Nerve‐sparing surgery reduces the risk of postoperative complications and can be optimised by the use of intraoperative frozen sections of the adjacent neurovascular structure (NeuroSAFE). The aims of this study were to evaluate the pathological outcomes of the NeuroSAFE technique and to develop a comprehensive algorithm for intraoperative clinical decision‐making.

Methods and results

Between September 2018 and May 2019, 491 NeuroSAFE procedures were performed in 258 patients undergoing radical prostatectomy; 74 of 491 (15.1%) NeuroSAFE specimens had positive surgical margins. As compared with the corresponding paraffin sections, NeuroSAFE had a positive predictive value and negative predictive value of 85.1% and 95.4%, respectively. In 72.2% of secondary neurovascular bundle resections prompted by a NeuroSAFE positive surgical margin, no tumour was present. These cases more often had a positive surgical margin of ≤1 mm (48.7% versus 20.0%; P = 0.001) and only one positive slide (69.2% versus 33.3%; P = 0.008). None of the nine patients with Gleason pattern 3 at the surgical margin, a positive surgical margin length of ≤1 mm and one positive slide had tumour in the secondary resection.

Conclusions

This study provides a systematic reporting template for pathological intraoperative NeuroSAFE evaluation, supporting intraoperative clinical decision‐making and comparison between prostate cancer operation centres.