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

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.

Assessing the Impact of Positive Surgical Margins on Mortality in Patients Who Underwent Robotic Radical Prostatectomy: 20 Years' Report from the EAU Robotic Urology Section Scientific Working Group

BACKGROUND

Positive surgical margins (PSMs) are frequent in patients undergoing radical prostatectomy (RP). The impact of PSMs on cancer-specific (CSM) and overall (OM) mortality has not yet been proved definitively.

OBJECTIVE

To evaluate whether the presence and the features of PSMs were associated with CSM and OM in patients who underwent robotic-assisted RP.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of 8141 patients underwent robotic-assisted RP with >10 yr of follow-up.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cox multivariable analyses assessed the impact of margin status (positive vs negative) and PSM features (negative vs <3 mm vs >3 mm vs multifocal) on the risk of CSM, OM, and biochemical recurrence (BCR) after adjusting for potential confounders. We repeated our analyses after stratifying patients according to clinical (Cancer of the Prostate Risk Assessment [CAPRA] categories) and pathological characteristics (adverse: pT 3-4 and/or grade group [GG] 4-5 and/or pN1 and/or prostate-specific antigen [PSA] persistence).

RESULTS AND LIMITATIONS

PSMs were found in 1348 patients (16%). Among these, 48 (3.6%) patients had multifocal PSMs. Overall, 1550 men experienced BCR and 898 men died, including 130 for prostate cancer. At Cox multivariable analyses, PSMs were associated with CSM in patients with adverse clinical (Intermediate risk: hazard ratio [HR]: 1.71, p = 0.048; high risk: HR: 2.20, p = 0.009) and pathological (HR: 1.79, p = 0.005) characteristics. Only multifocal PSMs were associated with CSM and OM in the whole population (HR for CSM: 4.68, p < 0.001; HR for OM: 1.82, p = 0.037) and in patients with adverse clinical (intermediate risk: HR for CSM: 7.26, p = 0.006; high risk: HR for CSM: 9.26, p < 0.001; HR for OM: 2.97, p = 0.006) and pathological (HR for CSM: 9.50, p < 0.001; HR for OM: 2.59, p = 0.001) characteristics. Potential limitations include a selection bias and a lack of information on the Gleason score at PSM location.

CONCLUSIONS

We did not find an association between unifocal PSMs and mortality. Conversely, our results underscore the importance of avoiding multifocal PSMs in patients with adverse clinical (intermediate- and high-risk CAPRA score) and pathological (GG ≥4, pT ≥3, pN1, or PSA persistence) characteristics, to enhance overall survival and reduce CSM.

PATIENT SUMMARY

In this study, we evaluated whether the presence and the characteristics of positive surgical margins were associated with mortality in patients who underwent robotic-assisted radical prostatectomy. We found that the presence of positive surgical margins, particularly multifocal margins, was associated with mortality only in patients with adverse clinical and pathological characteristics.

Intraoperative technologies to assess margin status during radical prostatectomy - a narrative review

Positive surgical margin (PSM) is a frequent concern for surgeons performing radical prostatectomy for prostate cancer (PCa). PSM are recognized as risk factors for earlier biochemical recurrence and expose patients to adjuvant or salvage treatments such as external radiotherapy and hormonotherapy. Several strategies have been established to reduce PSM rate, while still allowing safe nerve-sparing surgery. Precise preoperative staging by multiparametric magnetic resonance imaging (mpMRI) and fusion biopsy is recommended to identify suspicious areas of extracapsular extension (ECE) that warrant special attention during dissection. However, even with optimal imaging, ECE can be missed, some cancers are not well defined or visible, and capsular incision during surgery remains an issue. Hence, intraoperative frozen section techniques, such as the neurovascular structure-adjacent frozen section examination (NeuroSAFE) have been developed and lately widely disseminated. The NeuroSAFE technique reduces PSM rate while allowing higher rate of nerve-sparing surgery. However, its use is limited to high volume or expert center because of its high barrier-to-entry in terms of logistics, human resources and expertise, as well as cost. Also, NeuroSAFE is a time-consuming process, even in expert hands. To address these issues, several technologies have been developed for an ex vivo and in vivo use. Ex vivo technology such as fluorescent confocal microscopy and intraoperative PET-CT require the extraction of the specimen for preparation, and digital images acquisition. In vivo technology, such as augmented reality based on mpMRI images and PSMA-fluorescent guided surgery have the advantage to provide an intracorporeal analysis of the completeness of the resection. The current manuscript provides a narrative review of established techniques, and details several new and promising techniques for intraoperative PSM assessment.

Nerve-sparing radical prostatectomy using the neurovascular structure-adjacent frozen-section examination (NeuroSAFE): results after 20 years of experience

OBJECTIVES

To evaluate the long-term oncological outcomes and functional results of the neurovascular structure-adjacent frozen-section examination (NeuroSAFE) during nerve-sparing (NS) radical prostatectomy (RP).

MATERIALS AND METHODS

A 10-yr survival analysis on 11069 RPs performed with or without the NeuroSAFE, between January 2002 to June 2011 was carried out. In the NeuroSAFE cohort, the neurovascular structure-adjacent prostatic margins are removed and stained for cryo-sectioning during RP. In case of a PSM, partial or full removal of the neurovascular bundle was performed. The impact of NeuroSAFE on biochemical recurrence-free survival (BFS), salvage radiation therapy-free survival, metastasis-free survival, and prostate cancer-specific survival at 10 years was analyzed. 1-year (1-yr) erectile function (EF), 1-yr, and 2-yr continence rates were assessed in propensity score-based matched cohorts.

RESULTS

Median follow-up was 121 (IQR: 73, 156) months. No differences in BFS between NeuroSAFE and non-NeuroSAFE were recorded (10-yr BFS: NeuroSAFE vs non-Neurosafe, pT2: 81% vs 84%, p = 0.06; pT3a: 58% vs. 63%, p = 0.6; ≥pT3b: 22% vs. 27%, p = 0.99). No differences were found between the two groups in terms of sRFS (pT2: p = 0.1; pT3a: p = 0.4; ≥pT3b: p = 0.4) (Fig. 1B, Table 2), and MTS (pT2: p = 0.3; pT3a: p = 0.6; ≥pT3b: p = 0.9). The NeuroSAFE-navigated patients reported a better 1-yr EF than non-NeuroSAFE (68% vs. 58%, p = 0.02) and no differences in 1-yr and 2-yr continence rates (92.4% vs. 91.8%, and 93.4% vs. 93%, respectively). The main limitation is the retrospective study design.

CONCLUSIONS

While the NeuroSAFE approach did not show significant improvements in long-term oncologic or continence outcomes, it did provide an opportunity for a higher proportion of patients to improve postoperative functional results, possibly through increased nerve-sparing procedures.

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.

Impact of multiparametric magnetic resonance imaging targeted biopsy on functional outcomes in patients following robot-assisted laparoscopic radical prostatectomy

Introduction

Multiparametric magnetic resonance imaging guided prostate biopsy (mpMRI PBx) leads to a higher rate of successful nerve-sparing in robot-assisted laparoscopic prostatectomy (ns-RALP) for prostate cancer (PCa). This study aimed to evaluate the impact of mpMRI PBx compared to standard ultrasound-guided PBx on functional outcomes focusing on erectile function in patients following ns-RALP.

Material and methods

All RALPs performed between 01/2016 and 06/2021 were retrospectively stratified according to (attempted) ns vs. non ns RALPs and were then categorized based on the PBx technique (mpMRI PBx vs. standard PBx). We compared RALP outcomes such as pathological tumor stage, rates of secondary nerve resection (SNR) and positive surgical margin status (PSM). Furthermore, we explored the association between PBx-technique and patient-reported outcomes assessed 12 months after RALP using the prospectively collected 26-item Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. Chi-square tests and logistic regression analysis were conducted.

Results

A total of 849 RALPs included 517 (61%) procedures with (attempted) ns. Among these, 37.5% were diagnosed via preoperative mpMRI PBx. Patients with a preoperative standard PBx had a 57% higher association of PSM (p = 0.030) compared to patients with mpMRI PBx and a 24% higher risk of erectile dysfunction (ED) 12 months post RALP (p = 0.025). When ns was attempted, we observed a significantly higher rate of SNR in patients who underwent a standard PBx compared to those who received a mpMRI PBx (50.8% vs. 26.7%, p < 0.001) prior RALP. In comparison, upgrading occurred more often in the standard PBx group (50% vs. 40% mpMRI PBx, p = 0.008).

Conclusion

The combination of mpMRI PBx for PCa diagnosis followed by ns-RALP resulted in significantly fewer cases of SNR, better oncological outcomes and reduced incidence of ED 1 year after surgery. This included fewer PSM and a lower rate of postoperative tumor upgrading.

Three-dimensional automatic artificial intelligence driven augmented-reality selective biopsy during nerve-sparing robot-assisted radical prostatectomy: A feasibility and accuracy study

Objective

To evaluate the accuracy of our new three-dimensional (3D) automatic augmented reality (AAR) system guided by artificial intelligence in the identification of tumour's location at the level of the preserved neurovascular bundle (NVB) at the end of the extirpative phase of nerve-sparing robot-assisted radical prostatectomy.

Methods

In this prospective study, we enrolled patients with prostate cancer (clinical stages cT1c-3, cN0, and cM0) with a positive index lesion at target biopsy, suspicious for capsular contact or extracapsular extension at preoperative multiparametric magnetic resonance imaging. Patients underwent robot-assisted radical prostatectomy at San Luigi Gonzaga Hospital (Orbassano, Turin, Italy), from December 2020 to December 2021. At the end of extirpative phase, thanks to our new AAR artificial intelligence driven system, the virtual prostate 3D model allowed to identify the tumour's location at the level of the preserved NVB and to perform a selective excisional biopsy, sparing the remaining portion of the bundle. Perioperative and postoperative data were evaluated, especially focusing on the positive surgical margin (PSM) rates, potency, continence recovery, and biochemical recurrence.

Results

Thirty-four patients were enrolled. In 15 (44.1%) cases, the target lesion was in contact with the prostatic capsule at multiparametric magnetic resonance imaging (Wheeler grade L2) while in 19 (55.9%) cases extracapsular extension was detected (Wheeler grade L3). 3D AAR guided biopsies were negative in all pathological tumour stage 2 (pT2) patients while they revealed the presence of cancer in 14 cases in the pT3 cohort (14/16; 87.5%). PSM rates were 0% and 7.1% in the pathological stages pT2 and pT3 (<3 mm, Gleason score 3), respectively.

Conclusion

With the proposed 3D AAR system, it is possible to correctly identify the lesion's location on the NVB in 87.5% of pT3 patients and perform a 3D-guided tailored nerve-sparing even in locally advanced diseases, without compromising the oncological safety in terms of PSM rates.

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.

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.

The impact of 3D models on positive surgical margins after robot-assisted radical prostatectomy

PURPOSE

To evaluate the role of 3D models on positive surgical margin rate (PSM) rate in patients who underwent robot-assisted radical prostatectomy (RARP) compared to a no-3D control group. Secondarily, we evaluated the postoperative functional and oncological outcomes.

METHODS

Prospective study enrolling patients with localized prostate cancer (PCa) undergoing RARP with mp-MRI-based 3D model reconstruction, displayed in a cognitive or augmented-reality fashion, at our Centre from 01/2016 to 01/2020. A control no-3D group was extracted from the last two years of our Institutional RARP database. PSMr between the two groups was evaluated and multivariable linear regression (MLR) models were applied. Finally, Kaplan-Meier estimator was used to calculate biochemical recurrence at 12 months after the intervention.

RESULTS

160 patients were enrolled in the 3D Group, while 640 were selected for the Control Group. A more conservative NS approach was registered in the 3D Group (full NS 20.6% vs 12.7%; intermediate NS 38.1% vs 38.0%; standard NS 41.2% vs 49.2%; p = 0.02). 3D Group patients had lower PSM rates (25 vs. 35.1%, p = 0.01). At MLR models, the availability of 3D technology (p = 0.005) and the absence of extracapsular extension (ECE, p = 0.004) at mp-MRI were independent predictors of lower PSMr. Moreover, 3D model represented a significant protective factor for PSM in patients with ECE or pT3 disease.

CONCLUSION

The availability of 3D models during the intervention allows to modulate the NS approach, limiting the occurrence of PSM, especially in patients with ECE at mp-MRI or pT3 PCa.

Negative mpMRI Rules Out Extra-Prostatic Extension in Prostate Cancer before Robot-Assisted Radical Prostatectomy

Background: The accuracy of multi-parametric MRI (mpMRI) in the pre-operative staging of prostate cancer (PCa) remains controversial. Objective: The purpose of this study was to evaluate the ability of mpMRI to accurately predict PCa extra-prostatic extension (EPE) on a side-specific basis using a risk-stratified 5-point Likert scale. This study also aimed to assess the influence of mpMRI scan quality on diagnostic accuracy. Patients and Methods: We included 124 men who underwent robot-assisted RP (RARP) as part of the NeuroSAFE PROOF study at our centre. Three radiologists retrospectively reviewed mpMRI blinded to RP pathology and assigned a Likert score (1-5) for EPE on each side of the prostate. Each scan was also ascribed a Prostate Imaging Quality (PI-QUAL) score for assessing the quality of the mpMRI scan, where 1 represents the poorest and 5 represents the best diagnostic quality. Outcome measurements and statistical analyses: Diagnostic performance is presented for the binary classification of EPE, including 95% confidence intervals and the area under the receiver operating characteristic curve (AUC). Results: A total of 231 lobes from 121 men (mean age 56.9 years) were evaluated. Of these, 39 men (32.2%), or 43 lobes (18.6%), had EPE. A Likert score ≥3 had a sensitivity (SE), specificity (SP), NPV, and PPV of 90.4%, 52.3%, 96%, and 29.9%, respectively, and the AUC was 0.82 (95% CI: 0.77-0.86). The AUC was 0.76 (95% CI: 0.64-0.88), 0.78 (0.72-0.84), and 0.92 (0.88-0.96) for biparametric scans, PI-QUAL 1-3, and PI-QUAL 4-5 scans, respectively. Conclusions: MRI can be used effectively by genitourinary radiologists to rule out EPE and help inform surgical planning for men undergoing RARP. EPE prediction was more reliable when the MRI scan was (a) multi-parametric and (b) of a higher image quality according to the PI-QUAL scoring system.

Impact of mpMRI targeted biopsy on intraoperative nerve-sparing (NeuroSAFE) during robot-assisted laparoscopic radical prostatectomy

BACKGROUND

The aim of our study was to evaluate the impact of prostate biopsy technique (transrectal ultrasound (US)-prostate biopsy (PBx) versus multiparametric magnetic resonance imaging (mpMRI) targeted prostate biopsy (MRI-PBx) on intraoperative nerve-sparing and the rate of secondary neurovascular-bundle resection (SNR) in patients undergoing robot-assisted laparoscopic radical prostatectomy (RARP). A real-time investigation with a frozen-section examination (NeuroSAFE) microscopically excluded or confirmed prostate cancer invasion of the nerve structures resulting in preservation of the neurovascular bundle or SNR. Additionally, we analyzed risk factors related to SNR, such as longer operation time and postoperative complications.

METHODS

The total study cohort was stratified according to non-nerve-sparing versus nerve-sparing RARP. Patients with nerve-sparing approach were then stratified according to biopsy technique (PBx vs. MRI-PBx). Further, we compared PBx versus MRI-PBx according to SNR rate.

RESULTS

We included a total of 470 consecutive patients, who underwent RARP for PCa at our institution between January 2016 and December 2019. Patients with a preoperative MRI-PBx had a 2.12-fold higher chance of successful nerve-sparing (without SNR) compared to patients with PBx (p < 0.01). Patients with preoperative MRI-PBx required 73% less intraoperative SNR compared to patients with PBx (p < 0.0001). Prior MRI-PBx is thus a predictor for successful nerve-sparing RARP approach.

CONCLUSION

Preoperative MRI-PBx led to better oncological outcomes and less SNR. Young patients with good erectile function could benefit from a preoperative MRI-PBx before nerve-sparing RARP.

The association of a risk group with positive margin in the intraoperative and final pathology examination after robotic radical prostatectomy

Introduction

The aim of this study was to evaluate the risk of a positive margin in the intraoperative and final pathology depending on the risk group for biochemical recurrence in biopsy specimens after robot-assisted radical prostatectomy (RaRP) with sparing of the neurovascular bundles (NS).

Material and methods

The study was prospective and non-randomised. The intraoperative and final pathology examinations were performed in 65 consecutive patients treated with RaRP between 11.2019–08.2020. In the intraoperative examination, the site of the dissected neurovascular bundles and any suspicious places were examined. Patients were divided into 3 risk groups [according to the European Association of Urology (EAU) biochemical recurrence-risk stratification]. Due to the uncertain prognostic value of microscopic positive margins, 3 groups were identified: R0, Rmicro and R1.

Results

In the intraoperative examination, the distribution of risk groups in R0, Rmicro and R1 groups is similar (p = 0.132). In the postoperative study, the distribution of risk groups in each margin group is different, and is statistically significant (p <0.001). It has been shown that an increase in the risk group is an indicator of the occurrence of a positive margin in the final histopathological result regardless of the inclusion of Rmicro into R1 or into R0 by 2.68 and 6.52 times, respectively.

Conclusions

The preoperative risk group is an important factor for the occurrence of a positive margin, but only in the final examination and not in the intraoperative one. An intraoperative examination of the neurovascular bundles only is pointless and should be extended to the examination of the apex.

How molecular imaging will enable robotic precision surgery : The role of artificial intelligence, augmented reality, and navigation

Molecular imaging is one of the pillars of precision surgery. Its applications range from early diagnostics to therapy planning, execution, and the accurate assessment of outcomes. In particular, molecular imaging solutions are in high demand in minimally invasive surgical strategies, such as the substantially increasing field of robotic surgery. This review aims at connecting the molecular imaging and nuclear medicine community to the rapidly expanding armory of surgical medical devices. Such devices entail technologies ranging from artificial intelligence and computer-aided visualization technologies (software) to innovative molecular imaging modalities and surgical navigation (hardware). We discuss technologies based on their role at different steps of the surgical workflow, i.e., from surgical decision and planning, over to target localization and excision guidance, all the way to (back table) surgical verification. This provides a glimpse of how innovations from the technology fields can realize an exciting future for the molecular imaging and surgery communities.

[Organoids for the advancement of intraoperative diagnostic procedures]

In the context of cancer surgery, there is always a trade-off between oncological safety and preservation of function. This is especially true in pelvic surgery due to the close relationship to the pelvic floor muscles, blood supply and nerves. Currently, risk models, preoperative imaging, the surgeon's assessment, and the intraoperative frozen section serve as the basis for decision-making. New imaging techniques and standardization in frozen section have significantly improved this in recent years. However, limitations remain due to time delays as well as more difficult correct anatomical assignment in the follow-up. Alternative intraoperative techniques may overcome this limitation in the future. Patient-derived organoids have emerged as an important new research vehicle in recent years. They are based on tumor stem cells that, under special culture conditions, form three-dimensional replicas of the original tissue. This makes them ideally suited for testing individual system therapies but also as a validation technique for new intraoperative diagnostic procedures. The Research Training Group 2543/I, which is funded by the German Research Foundation, is researching the potential of new diagnostic methods in an interdisciplinary team regarding validation in addition to intraoperative frozen sections.