Neurovascular structure-adjacent frozen-section examination (NeuroSAFE) increases nerve-sparing frequency and reduces positive surgical margins in open and robot-assisted laparoscopic radical prostatectomy: experience after 11,069 consecutive patients

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.

Effects of different surgical modalities for nerve-sparing robot-assisted radical prostatectomy on postoperative erectile function: a systematic review and one-arm meta-analysis

Maintaining erectile function is an important quality of life issue for patients with localized prostate cancer treated with robotic-assisted radical prostatectomy (RARP). However, most existing studies are retrospective and inherently weak and cannot conclude which NS approach is most effective in restoring function in patients. We therefore performed a consistent and objective assessment of sexual function outcomes in RARP using different nerve-sparing methods to optimize postoperative outcomes. A systematic review and meta-analysis was performed based on PRISMA and STROBE statement criteria. Statistical analysis was performed using StataMP software version 14. The Newcastle-Ottawa scale was used to assess the risk of bias. This single-arm meta-analysis included 3 randomized controlled trials and 14 cohort studies with a total of 3756 patients. Our meta-analysis found that patients had the highest efficiency rate of 0.86 (0.78, 0.93) after the NS technique using the retrograde method. Overall, there are significant differences between RARP NS techniques and outcomes, and the ideal technical strategy to optimize outcomes remains controversial. However, there is consensus on the importance of careful separation, dissection of the NVB, reduction of traction and thermal injury, and preservation of the fascia around the prostate. We still need more well-designed randomized controlled trials with videos describing the details of the different surgical techniques before they can be replicated.

Evaluation of margins during radical prostatectomy: confocal microscopy vs frozen section analysis

OBJECTIVES

To test the performance of ex vivo fluorescence confocal microscopy (FCM; Vivascope 2500M-G4), as compared to intra-operative frozen section (IFS) analysis, to evaluate surgical margins during robot-assisted radical prostatectomy (RARP), with final pathology as the reference standard.

METHODS

Overall, 54 margins in 45 patients treated with RARP were analysed with: (1) ex vivo FCM; (2) IFS analysis; and (3) final pathology. FCM margins were evaluated by two different pathologists (experienced [M.I.: 10 years] vs highly experienced [G.R.: >30 years]) as strongly negative, probably negative, doubtful, probably positive, or strongly positive. First, inter-observer agreement (Cohen's κ) between pathologists was tested. Second, we reported the sensitivity, specificity, positive predictive (PPV) and negative predictive value (NPV) of ex vivo FCM. Finally, agreement between ex vivo FCM and IFS analysis (Cohen's κ) was reported. For all analyses, four combinations of FCM results were evaluated.

RESULTS

At ex vivo FCM, the inter-observer agreement between pathologists ranged from moderate (κ = 0.74) to almost perfect (κ = 0.90), according to the four categories of results. Indeed, at ex vivo FCM, the highly experienced pathologist reached the best balance between sensitivity (70.5%) specificity (91.8%), PPV (80.0%) and NPV (87.1%). Conversely, on IFS analysis, the sensitivity, specificity, PPV and NPV were, respectively, 88.2% vs 100% vs 100% vs 94.8%. The agreement between the ex vivo FCM and IFS analyses ranged from moderate (κ = 0.62) to strong (κ = 0.86), according to the four categories of results.

CONCLUSION

Evaluation of prostate margins at ex vivo FCM appears to be feasible and reliable. The agreement between readers encourages its widespread use in daily practice. Nevertheless, as of today, the performance of FCM seems to be sub-par when compared to the established standard of care (IFS analysis).

Preoperative multidisciplinary team meeting improves the incidence of positive margins in pathological T2 prostate cancer

PURPOSE

Positive surgical margins (PSM) after robot-assisted radical prostatectomy (RARP) for prostate cancer (PCa) can increase the risk of biochemical recurrence and PCa-specific mortality. We aimed to evaluate the impact of multidisciplinary team meetings (MDTM) on reducing the incidence of PSM following RARP.

METHODS

We retrospectively collected the clinical data of consecutive patients undergoing RARP at Hiroshima University between February 2017 and October 2023. The MDTM, comprising a radiologist, uropathologist, and urologist, reviewed the preoperative magnetic resonance imaging (MRI) and prostate biopsy results of each patient before RARP and considered the areas requiring attention during RARP. Surgeons were categorized as experienced or non-experienced based on the number of RARP procedures performed.

RESULTS

In the pT2 population, the PSM rate was significantly lower in cases evaluated using the MDTM than in those not (11.1% vs. 24.0%; p = 0.0067). Cox regression analysis identified that a PSA level > 7 ng/mL (hazard ratio 2.2799) and nerve-sparing procedures (hazard ratio 2.2619) were independent predictors of increased PSM risk while conducting an MDTM (hazard ratio 0.4773) was an independent predictor of reduced PSM risk in the pT2 population. In the pathological T3 population, there was no significant difference in PSM rates between cases evaluated and not evaluated at an MDTM. In cases evaluated at an MDTM, similar PSM rates were observed regardless of surgeon experience (10.4% for non-experienced and 11.9% for experienced surgeons; p = 0.9999).

CONCLUSIONS

An MDTM can improve the PSM rate of pT2 PCa following RARP.

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.

Bicenter validation of a risk model for the preoperative prediction of extraprostatic extension of localized prostate cancer combining clinical and multiparametric MRI parameters

BACKGROUND

This study aimed to validate a previously published risk model (RM) which combines clinical and multiparametric MRI (mpMRI) parameters to predict extraprostatic extension (EPE) of prostate cancer (PC) prior to radical prostatectomy (RP).

MATERIALS AND METHODS

A previously published RM combining clinical with mpMRI parameters including European Society of Urogenital Radiology (ESUR) classification for EPE was retrospectively evaluated in a cohort of two urological university hospitals in Germany. Consecutive patients (n = 205, January 2015 -June 2021) with available preoperative MRI images, clinical information including PSA, prostate volume, ESUR classification for EPE, histopathological results of MRI-fusion biopsy and RP specimen were included. Validation was performed by receiver operating characteristic analysis and calibration plots. The RM's performance was compared to ESUR criteria.

RESULTS

Histopathological T3 stage was detected in 43% of the patients (n = 89); 45% at Essen and 42% at Düsseldorf. Discrimination performance between pT2 and pT3 of the RM in the entire cohort was AUC = 0.86 (AUC = 0.88 at site 1 and AUC = 0.85 at site 2). Calibration was good over the entire probability range. The discrimination performance of ESUR classification alone was comparable (AUC = 0.87).

CONCLUSIONS

The RM showed good discriminative performance to predict EPE for decision-making for RP as a patient-tailored risk stratification. However, when experienced MRI reading is available, standardized MRI reading with ESUR scoring is comparable regarding information outcome. A main limitation is the potentially limited transferability to other populations because of the high prevalence of EPE in our subgroups.

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.

Feasibility of Diffuse Reflection Spectroscopy for Intraoperative Margin Assessment During Prostatectomy

Background and objective

A positive surgical margin (PSM) occurs in up to 32% of patients undergoing robot-assisted radical prostatectomy (RARP). Diffuse reflectance spectroscopy (DRS), which measures tissue composition according to its optical properties, can potentially be used for real-time PSM detection during RARP. Our objective was to assess the feasibility of DRS in distinguishing prostate cancer from benign tissue in RARP specimens.

Methods

In a single-center prospective study, DRS measurements were taken ex vivo for RARP specimens from 59 patients with biopsy-proven prostate carcinoma. Discriminating features from the DRS spectra were used to create a machine learning-based classification algorithm. The data were split patient-wise into training (70%) and testing (30%) sets, with ten iterations to ensure algorithm robustness. The average sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) from ten classification iterations were calculated.

Key findings and limitations

We collected 542 DRS measurements, of which 53% were tumor and 47% were healthy-tissue measurements. Twenty discriminating features from the DRS spectra were used as the input for a support vector machine model. This model achieved average sensitivity of 89%, specificity of 82%, accuracy of 85%, and AUC of 0.91 for the test set. Limitations include the binary label input for classification.

Conclusions and clinical implications

DRS can potentially discriminate prostate cancer from benign tissue. Before implementing the technique in clinical practice, further research is needed to assess its performance on heterogeneous tissue volumes and measurements from the prostate surface.

Patient summary

We looked at the ability of a technique called diffuse reflectance spectroscopy to guide surgeons in discriminating prostate cancer tissue from benign prostate tissue in real time during prostate cancer surgery. Our study showed promising results in an experimental setting. Future research will focus on bringing this technique to clinical practice.

Urinary continence outcomes, surgical margin status, and complications after radical prostatectomy in 2,141 German patients treated in one high-volume inpatient rehabilitation clinic in 2022

PURPOSE

To identify independent predictors of urinary continence and report early complications after radical prostatectomy (RP) in a large, contemporary German cohort.

METHODS

Urinary incontinence data of patients undergoing 3-week inpatient rehabilitation (IR) after RP were prospectively assessed by 24-hr pad test and uroflowmetry at the beginning and the end of IR, respectively. Lymphoceles were assessed prospectively by ultrasound. Tumor and patient characteristics, and information on urinary leakage on initial cystography were retrospectively extracted from discharge letters and surgical reports. Regression analyses were performed to identify predictors of urinary continence at the beginning of IR.

RESULTS

Overall, 2,141 patients were included in the final analyses. Anastomotic leakage on the initial cystography and lymphoceles were found in 11.4% and 30.8% of patients, respectively. Intervention for a symptomatic lymphocele was required in 4.2% of patients. At the end of IR, 54.2% of patients were continent, while the median urine loss decreased to 73 g (interquartile range 15-321). Multivariable logistic regression analysis identified age and diabetes mellitus as independent negative predictors, but nerve-sparing surgery as an independent positive predictor of urinary continence (each p < 0.001). Multivariable linear regression analysis showed that 24-hr urine loss increased by 7 g with each year of life (p < 0.001), was 79 g higher in patients with diabetes mellitus (p = 0.007), and 175 g lower in patients with NS (p < 0.001).

CONCLUSION

Age, diabetes mellitus, and NS are significantly associated with continence outcomes in the early period after RP. Our analyses may help clinicians to pre-operatively counsel patients on potential surgical outcomes.

Current clinical applications of Cerenkov luminescence for intraoperative molecular imaging

BACKGROUND

Cerenkov luminescence imaging (CLI) is a new emerging technology that can be used for optical imaging of approved radiotracers, both in a preclinical, and even more recently, in a clinical context with rapid imaging times, low costs, and detection in real-time (Grootendorst et al. Clin Transl Imaging 4(5):353-66, 2016); Wang et al. Photonics 9(6):390, 2022). This brief review provides an overview of clinical applications of CLI with a focus on intraoperative margin assessment (IMA) to address shortcomings and provide insight for future work in this application.

METHODS

A literature review was performed using PubMed using the search words Cerenkov luminescence imaging (CLI), intraoperative margin assessment (IMA), and image-guided surgery. Articles were selected based on title, abstract, content, and application.

RESULTS

Original research was summarized to examine advantages and limitations of CLI compared to other modalities for IMA. The characteristics of Cerenkov luminescence (CL) are defined, and results from relevant clinical trials are discussed. Prospects of ongoing clinical trials are reviewed, along with technological advancements related to CLI.

CONCLUSION

CLI is a proven method for molecular imaging and shows feasibility for determining intraoperative margins if future work involves establishing quantitative approaches for attenuation and scattering, depth analysis, and radiation safety for CLI at a larger scale.

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.

Outcomes after precision prostatectomy: safety, efficacy and transference of skills

PURPOSE

Precision Prostatectomy (PP) is a viable treatment option for men with unilateral dominant cancer who are interested in preserving functional outcomes. To date, the data published about the outcomes of this technique has come from a single center only (Henry Ford - HF). We present the surgical, functional, and oncological outcomes of the first series of patients to undergo PP outside of HF, to demonstrate the safety and reproducibility of the technique.

METHODS

Between 2022 and 2023, PP was offered to select patients who were interested in preserving their functional status. Men who underwent PP were followed at 3 monthly intervals; information regarding their functional status was simultaneously obtained. Men who had biochemical recurrence were advised to undergo remnant biopsy. If residual cancer was detected, then remnant removal was performed.

RESULTS

The median age and median PSA of the study group was 63 years and 6.89 ng/ml respectively. The median operative and console times were 196.5 and 154 minutes. No intra-operative complications were noted. Three patients had a total of three post-operative complications. Three patients had biochemical recurrence; cancer was not detected in any of these patients on postoperative biopsies of the prostatic remnant. At 12 months, 91% of patients reported using 0 pads/day and 90.9% of pre-operatively potent patients were potent at 12 months.

CONCLUSION

PP is a safe and reproducible technique that can ensure cancer control and preservation of functional status in select patients. Further studies with large sample sizes and longer follow-up are required to ascertain the long-term outcomes of this surgical technique.

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.

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.

Precise Prediction of Long-Term Urinary Incontinence after Robot-Assisted Laparoscopic Radical Prostatectomy by Readily Accessible "Everyday" Diagnostics during Post-Surgical Hospitalization

Aim and Objectives: We aimed to test the predictive value of readily accessible and easily performed post-surgical "bedside tests" on their validity of long-term urinary incontinence (UI) (≥12 months) in patients following robot-assisted laparoscopic radical prostatectomy (RALP). Material and Methods: Patients undergoing RALP between July 2020 and March 2021 were prospectively included and subdivided into two groups based on their pad usage after 12 months (0 vs. ≥1 pad). After catheter removal, patients performed a 1 h pad test, documented the need for pad change in a micturition protocol and received post-voiding residual urine volume ultrasound. Univariate and multivariable analyses were used to demonstrate the predictive value of easily accessible tests applied after catheter removal for UI following RALP. Results: Of 109 patients, 47 (43%) had to use at least one pad (vs. 62 (57%) zero pads) after 12 months. Univariate testing showed a significant difference in urine loss between both groups evaluated by the 1 h pad test performed within 24 h after catheter removal (70% < 10 mL, vs. 30% ≥ 10 mL, p = 0.004) and in the need for pad change within the first 24 h after catheter removal (14% dry pads vs. 86% wet pads, p = 0.003). In multivariable analyses, the combination of both tests (synoptical incontinence score) could be confirmed as an independent predictor for UI after 12 months (p = 0.011). Conclusions: Readily accessible "everyday" diagnostics (pad test/change of pads after catheter removal) following RALP seem to be associated with a higher rate of long-term UI. This finding is crucial since patients with a potentially higher need for patient education and counselling can be identified using these readily accessible tests. This could lead to a higher patient satisfaction and improved outcomes.

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.

Accuracy of Ex-vivo Fluorescence Confocal Microscopy in Margin Assessment of Solid Tumors: A Systematic Review

Fluorescence confocal microscopy (FCM) is a novel technology that enables rapid high-resolution digital imaging of non-formalin-fixed tissue specimens and offers real-time positive surgical margin identification. In this systematic review, we evaluated the accuracy metrics of ex vivo FCM for intraoperative margin assessment of different tumor types. A systematic search of MEDLINE via PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus was performed for relevant papers (PROSPERO ID: CRD42022372558). We included 14 studies evaluating four types of microscopes in six different tumor types, including breast, prostate, central nervous system, kidney, bladder, and conjunctival tumors. Using the Quality Assessment of Diagnostic Accuracy Studies tool, we identified a high risk of bias in patient selection (21%) and index test (36%) of the included studies. Overall, we found that FCM has good accuracy metrics in all tumor types, with high sensitivity and specificity (>80%) and almost perfect concordance (>90%) against final pathology results. Despite these promising findings, the quality of the available evidence and bias concerns highlight the need for adequately designed studies to further define the role of ex vivo FCM in replacing the frozen section as the tool of choice for intraoperative margin assessment.

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.

Decipher Score predicts prostate specific antigen persistence after prostatectomy

BACKGROUND

The aim of this study was to evaluate genomic risk of patients with persistent prostate specific antigen (PSA) using mRNA expression analysis and a validated prognostic genomic-risk classifier.

METHODS

Monocentric retrospective study including all patients who underwent radical prostatectomy (RP) by one surgeon and Decipher Test from October 2013 to December 2018. PSA persistent population was defined as all patients with two consecutive PSA>0.1 ng/mL at follow-up after the surgery. Neurovascular Structure-adjacent Frozen-section Examination (NeuroSAFE) was performed intraoperatively for research of positive surgical margins. Multivariate analysis was performed for persistent PSA (pPSA) predictors. A specific localized, organ-confined, and negative margins sub-population with PSA persistence was compared to a similar sub-population without PSA persistence for genomic differential expression analyses.

RESULTS

A total of 564 patients were included and 61 of them had pPSA. Preoperative PSA was higher in the PSA persistent group (11.6 [6.4, 21.2] vs. 6.2 [4.7, 9.2] P=0.00010), as well as PSA density (PSAd) (0.3 [0.2, 0.5] vs. 0.2 [0.1, 0.3] P=0.0001). Postoperative characteristics, Gleason Score, and positive surgical margins were significantly higher in the PSA persistent population. 31 patients had pPSA in our specific subpopulation and were compared to 217 patients with no pPSA. On multivariate analysis, only Decipher Score (OR=5.64 [1.28; 24.89], P=0.022) and preoperative PSA (OR=1.06, [1.02; 1.09], P=0.001) were significant predictors for PSA persistence. We found two genes to be significantly upregulated with a 2.5-fold change in our specific subpopulation (SERPINB11 and PDE11A).

CONCLUSIONS

We found unique genomic features of patients with pPSA, whilst confirming previous clinical findings that this condition behaves to a worse prognosis. Given this high genomic risk, further imaging studies should be performed to select patients for early treatment intensification.

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.

Clinical outcomes for men with positive surgical margins after radical prostatectomy-results from the South Australian Prostate Cancer Clinical Outcomes Collaborative community-based registry

Objective

Positive surgical margins (PSMs) after radical prostatectomy (RP) indicate failure of surgery to completely clear cancer. PSMs confer an increased risk of biochemical recurrence (BCR), but how more robust outcomes are affected is unclear. This study investigated factors associated with PSMs following RP and determined their impact on clinical outcomes (BCR, second treatment [radiotherapy and/or androgen deprivation therapy], and prostate cancer-specific mortality [PCSM]).

Methods

The study cohort included men diagnosed with prostate cancer (pT2-3b/N0/M0) between January 1998 and June 2016 who underwent RP from the South Australian Prostate Cancer Clinical Outcomes Collaborative database. Factors associated with risk of PSMs were identified using Poisson regression. The impact of PSMs on clinical outcomes (BCR, second treatment, and PCSM) was assessed using competing risk regression.

Results

Of the 2827 eligible participants, 28% had PSMs-10% apical, 6% bladder neck, 17% posterolateral, and 5% at multiple locations. Median follow-up was 9.6 years with 81 deaths from prostate cancer recorded. Likelihood of PSM increased with higher pathological grade and pathological tumor stage, and greater tumour volume, but decreased with increasing surgeon volume (odds ratio [OR]: 0.93; 95% confidence interval [CI]: 0.88-0.98, per 100 previous prostatectomies). PSMs were associated with increased risk of BCR (adjusted sub-distribution hazard ratio [sHR] 2.5; 95% CI 2.1-3.1) and second treatment (sHR 2.9; 95% CI 2.4-3.5). Risk of BCR was increased similarly for each PSM location, but was higher for multiple margin sites. We found no association between PSMs and PCSM.

Conclusion

Our findings support previous research suggesting that PSMs are not independently associated with PCSM despite strong association with BCR. Reducing PSM rates remains an important objective, given the higher likelihood of secondary treatment with associated comorbidities.

Robot-Assisted Laparoscopic Prostatectomy Experience and Pathological Quality: Are They Always Linked?

Objective: We investigated whether pathological outcomes improved with experience and surgeon generation after robot-assisted laparoscopic prostatectomy (RALP). Materials and Methods: The study included 1338 patients who underwent RALP between February 2010 and April 2020. We created learning curves for pelvic lymph node dissection (PLND), number of lymph nodes (LNs) removed, and positive surgical margin (PSM) after adjustment for confounders. We compared the outcomes between the first and second generation of surgeons in regression models. Results: The learning curve regarding PLND indications showed a significant increase with experience for the first generation, whereas the second generation had a learning curve that remained flat at a higher level (92.3%) and significantly better than the first generation (p < 0.001). Similarly, the number of LN removed showed a significant increase with experience in both generations, but the overall median number of LN removed was significantly higher in the second generation compared with the first generation (12 vs 10, p < 0.001). However, the learning curve for PSM remained flat at ∼20% after adjustment and did not show improvement with experience in both generations of surgeons (p = 0.794). Conclusions: Surgeons showed improvement with experience and education with RALP with respect to the indications for PLND and number of LNs removed. However, there was no improvement over time and generations for PSM. Experience based solely on the number of patients operated on is not an intrinsic factor in the pathological quality of RALP. Factors other than experience may also play a role in oncologic improvement.

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.

Intraoperative Molecular Positron Emission Tomography Imaging for Intraoperative Assessment of Radical Prostatectomy Specimens

In this prospective two-center feasibility study, we evaluate the diagnostic value of intraoperative ex vivo specimenPET/CT imaging of radical prostatectomy (RP) and lymphadenectomy specimens. Ten patients with high-risk prostate cancer underwent clinical prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) preoperatively on the day of surgery. Six patients received ⁶⁸Ga-PSMA-11 and four ¹⁸F-PSMA-1007. Radioactivity of the resected specimen was measured again using a novel specimenPET/CT device (AURA10; XEOS Medical, Gent, Belgium) developed for intraoperative margin assessment. All index lesions of staging multiparametric magnetic resonance imaging could be visualized. Overall, specimenPET/CT correlated well with conventional PET/CT regarding detection of suspicious tracer foci (Pearson coefficient 0.935). In addition, specimenPET/CT demonstrated all lymph node metastases detected on conventional PET/CT (n = 3), as well as three previously undetected lymph node metastases. Importantly, all positive or close (<1 mm) surgical margins could be visualized in agreement with histopathology. In conclusion, specimenPET/CT enables detection of PSMA-avid lesions and warrants further investigation to tailor RP, based on a good correlation with final pathology. Future trials will prospectively compare ex vivo specimenPET/CT with a frozen section analysis for the detection of positive surgical margins and assessment of biochemical recurrence-free survival.

Patient summary

In this report, we examined prostatectomy and lymphadenectomy specimens for suspicious positron emission tomography (PET) signals after preoperative tracer injection. It was found that in all cases, a good signal could be visualized, with a promising correlation of surface assessment compared with histopathology. We conclude that specimenPET imaging is feasible and may help improve oncological outcomes in the future.

3D-Reconstructed Contact Surface Area and Tumour Volume on Magnetic Resonance Imaging Improve the Prediction of Extraprostatic Extension of Prostate Cancer

This study is to determine whether the volume and contact surface area (CSA) of a tumour with an adjacent prostate capsule on MRI in a three-dimensional (3D) model that can predict side-specific extraprostatic extension (EPE) at radical prostatectomy (RP). Patients with localised prostate cancer (PCa) who underwent robot-assisted RP between July 2015 and March 2021 were included in this retrospective study. MRI-based 3D prostate models incorporating the PCa volume and location were reconstructed. The tumour volume and surface variables were extracted. For the prostate-to-tumour and tumour-to-prostate CSAs, the areas in which the distances were ≤ 1, ≤ 2, ≤ 3, ≤ 4, and ≤ 5 mm were defined, and their surface (cm2) were determined. Differences in prostate sides with and without pathological EPE were analysed. Multivariable logistic regression analysis to find independent predictors of EPE. Overall, 75/302 (25%) prostate sides showed pathological EPE. Prostate sides with EPE had higher cT-stage, higher PSA density, higher percentage of positive biopsy cores, higher biopsy Gleason scores, higher radiological tumour stage, larger tumour volumes, larger prostate CSA, and larger tumour CSA (all p < 0.001). Multivariable logistic regression analysis showed that the radiological tumour stage (p = 0.001), tumour volume (p < 0.001), prostate CSA (p < 0.001), and tumour CSA (p ≤ 0.001) were independent predictors of pathological EPE. A 3D reconstruction of tumour locations in the prostate improves prediction of extraprostatic extension. Tumours with a higher 3D-reconstructed volume, a higher surface area of tumour in contact with the prostate capsule, and higher surface area of prostate capsule in contact with the tumour are at increased risk of side-specific extraprostatic extension.

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.

Intra-operative fluorescence-based detection of positive surgical margins during radical prostatectomy: Lessons learned from a pilot ex vivo translational study

OBJECTIVES

Nerve-sparing techniques during radical prostatectomy have been associated with an increased risk of positive surgical margins. The intra-operative detection of residual prostatic tissue could help mitigate this risk. The objectives of the present study were to assess the feasibility of using an anti-prostate-specific membrane antigen (anti-PSMA) antibody conjugated with a fluorophore to characterize fresh prostate tissue as prostatic or non-prostatic for intra-operative surgical margin detection.

METHODS

Fresh prostatic tissue samples were collected from transurethral resections of the prostate (TURP) or prostate biopsies, and either immunolabelled with anti-PSMA antibody conjugated with Alexa Fluor 488 or used as controls. A dedicated, laparoscopy-compliant fluorescence device was developed for real-time fluorescence detection. Confocal microscopy was used as the gold standard for comparison. Spectral unmixing was used to distinguish specific, Alexa Fluor 488 fluorescence from nonspecific autofluorescence.

RESULTS

The average peak wavelength of the immuno-labeled TURP samples (n = 4) was 541.7 ± 0.9 nm and of the control samples (n = 4) was 540.8 ± 2.2 nm. Spectral unmixing revealed that these similar measures were explained by significant autofluorescence, linked to electrocautery. Three biopsy samples were then obtained from seven patients and also displayed significant nonspecific fluorescence, raising questions regarding the reproducibility of the fixation of the anti-PSMA antibodies on the samples. Comparing the fluorescence results with final pathology proved challenging due to the small sample size and tissue alterations.

CONCLUSIONS

This study showed similar fluorescence of immuno-labeled prostate tissue samples and controls, failing to demonstrate the feasibility of intra-operative margin detection using PSMA immuno-labeling, due to marked tissue autofluorescence. We successfully developed a fluorescence device that could be used intraoperatively in a laparoscopic setting. Use of the infrared range as well as newly available antibodies could prove interesting options for future research.

Full functional-length urethral sphincter- and neurovascular bundle preservation improves long-term continence rates after robotic-assisted radical prostatectomy

The objective of the study was to test the impact of implementing standard full functional-length urethral sphincter (FFLU) and neurovascular bundle preservation (NVBP) with intraoperative frozen section technique (IFT) on long-term urinary continence in patients undergoing robotic-assisted radical prostatectomy (RARP). We relied on an institutional tertiary-care database to identify patients who underwent RARP between 01/2014 and 09/2019. Until 10/2017, FFLU was not performed and decision for NVBP was taken without IFT. From 11/2017, FFLU and IFT-guided NVBP was routinely performed in all patients undergoing RARP. Long-term continence (≥ 12 months) was defined as the usage of no or one safety- pad. Uni- and multivariable logistic regression models tested the correlation between surgical approach (standard vs FFLU + NVBP) and long-term continence. Covariates consisted of age, body mass index, prostate volume and extraprostatic extension of tumor. The study cohort consisted of 142 patients, with equally sized groups for standard vs FFLU + NVBP RARP (68 vs 74 patients). Routine FFLU + NVBP implementation resulted in a long-term continence rate of 91%, compared to 63% in standard RARP (p < 0.001). Following FFLU + NVBP RARP, 5% needed 1-2, 4% 3-5 pads/24 h and no patient (0%) suffered severe long-term incontinence (> 5 pads/24 h). No significant differences in patient or tumor characteristics were recorded between both groups. In multivariable logistic regression models, FFLU + NVBP was a robust predictor for continence (Odds ratio [OR]: 7.62; 95% CI 2.51-27.36; p < 0.001). Implementation of FFLU and NVBP in patients undergoing RARP results in improved long-term continence rates of 91%.

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.

Radiation Protection and Occupational Exposure on 68Ga-PSMA-11-Based Cerenkov Luminescence Imaging Procedures in Robot-Assisted Prostatectomy

Cerenkov luminescence imaging (CLI) was successfully implemented in the intraoperative context as a form of radioguided cancer surgery, showing promise in the detection of surgical margins during robot-assisted radical prostatectomy. The present study was designed to provide a quantitative description of the occupational radiation exposure of surgery and histopathology personnel from CLI-guided robot-assisted radical prostatectomy after the injection of ⁶⁸Ga-PSMA-11 in a single-injection PET/CT CLI protocol. Methods: Ten patients with preoperative ⁶⁸Ga-PSMA-11 administration and intraoperative CLI were included. Patient dose rate was measured before PET/CT (n = 10) and after PET/CT (n = 5) at a 1-m distance for 4 patient regions (head [A], right side [B], left side [C], and feet [D]). Electronic personal dosimetry (EPD) was used for intraoperative occupational exposure (n = 10). Measurements included the first surgical assistant and scrub nurse at the operating table and the CLI imager/surgeon at the robotic console and encompassed the whole duration of surgery and CLI image acquisition. An estimation of the exposure of histopathology personnel was performed by measuring prostate specimens (n = 8) with a germanium detector. Results: The measured dose rate value before PET/CT was 5.3 ± 0.9 (average ± SD) μSv/h. This value corresponds to a patient-specific dose rate constant for positions B and C of 0.047 μSv/h⋅MBq. The average dose rate value after PET/CT was 1.04 ± 1.00 μSv/h. The patient-specific dose rate constant values corresponding to regions A to D were 0.011, 0.026, 0.024, and 0.003 μSv/h⋅MBq, respectively. EPD readings revealed average personal equivalent doses of 9.0 ± 7.1, 3.3 ± 3.9, and 0.7 ± 0.7 μSv for the first surgical assistant, scrub nurse, and CLI imager/surgeon, respectively. The median germanium detector-measured activity of the prostate specimen was 2.96 kBq (interquartile range, 2.23-7.65 kBq). Conclusion: Single-injection ⁶⁸Ga-PSMA-11 PET/CT CLI procedures are associated with a reasonable occupational exposure level, if kept under 110 procedures per year. Excised prostate specimen radionuclide content was below the exemption level for ⁶⁸Ga. Dose rate-based calculations provide a robust estimation for EPD measurements.

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.

Impact of positive surgical margin length and Gleason grade at the margin on oncologic outcomes in patients with nonorgan-confined prostate cancer

PURPOSE

Positive surgical margins (PSM) represent a poor prognostic factor at radical prostatectomy (RP). To investigate the impact of PSM, its length, the focality and the Gleason grade at the PSM, on the oncologic outcomes in nonorgan-confined RP patients.

METHODS

Within a high-volume center database, we identified patients who harbored non-organ-confined (pT3) prostate cancer (PCa) at RP between 2010 and 2016. Only patients without lymph node invasion were included. Kaplan-Meier analyses and multivariable Cox regression models were used to test the effect of PSM on biochemical recurrence (BCR), metastasis, and cancer-specific death after RP in patients without adjuvant radiotherapy.

RESULTS

Overall, 3705 patients were identified. Of those, 27.2% (n = 1007) harbored PSM. At 96 months after RP, BCR-free, metastasis-free and cancer-specific survival was 41.6 versus 57.5%, 82.7 versus 88.6%, and 94.7 versus 98.5% for patients with versus without PSM (all p < 0.001). BCR-free, metastasis-free and cancer-specific survival rates at 96 months were 56.7 versus 26.5% (p < 0.001), 94.4 versus 67.4% (p < 0.001), and 100.0 versus 87.1% (p < 0.01) for Gleason pattern 3 versus ≥ 4 at the margin and 45.0 versus 27.8% (p < 0.01), 83.3 versus 82.3% (p = 0.2), and 95.2 versus 92.7% (p = 0.3) for <4 mm versus ≥4 mm length of margin. In multivariable Cox models PSM was an independent predictor for BCR (hazard ratio [HR]:1.53, p < 0.001) and cancer-specific death (HR:2.75, p = 0.02). In subgroups of patients with PSM only, Gleason ≥ 4 at the margin (HR:1.60, p < 0.01) and length of PSM (HR:1.02, p < 0.05) was an independent predictor of BCR.

CONCLUSION

PSM represents an independent predictor for worse oncologic outcome in nonorgan-confined PCa at RP. Gleason ≥ 4 at the margin was associated with the development of BCR, metastasis, and with cancer-specific death after RP. Next to margin status, Gleason at the margin and its length carry important information that should be reported for the specimen.

Concordance between Preoperative mpMRI and Pathological Stage and Its Influence on Nerve-Sparing Surgery in Patients with High-Risk Prostate Cancer

Background: We aimed to determine the concordance between the radiologic stage (rT), using multiparametric magnetic resonance imaging (mpMRI), and pathologic stage (pT) in patients with high-risk prostate cancer and its influence on nerve-sparing surgery compared to the use of the intraoperative frozen section technique (IFST). Methods: The concordance between rT and pT and the rates of nerve-sparing surgery and positive surgical margin were assessed for patients with high-risk prostate cancer who underwent radical prostatectomy. Results: The concordance between the rT and pT stages was shown in 66.4% (n = 77) of patients with clinical high-risk prostate cancer. The detection of patients with extraprostatic disease (≥pT3) by preoperative mpMRI showed a sensitivity, negative predictive value and accuracy of 65.1%, 51.7% and 67.5%. In addition to the suspicion of extraprostatic disease in mpMRI (≥rT3), 84.5% (n = 56) of patients with ≥rT3 underwent primary nerve-sparing surgery with IFST, resulting in 94.7% (n = 54) of men with at least unilateral nerve-sparing surgery after secondary resection with a positive surgical margin rate related to an IFST of 1.8% (n = 1). Conclusion: Patients with rT3 should not be immediately excluded from nerve-sparing surgery, as by using IFST some of these patients can safely undergo nerve-sparing surgery.

Different Nerve-Sparing Techniques during Radical Prostatectomy and Their Impact on Functional Outcomes

Simple Summary

Optimum preservation of potency and continence after radical prostatectomy (RP) are equally important surgical endpoints as cancer control itself. Nerve-sparing technique during RP has a major impact to both oncological and functional outcomes of the procedure and various different techniques have been developed aiming to optimize its outcomes. This literature review aims to summarize all different nerve-sparing techniques applied during RP from its first description from Patrick C. Walsh to its newer trends. The review underlines that optimum nerve-sparing expands far beyond recognising and preserving the anatomical integrity of the neurovascular bundles. It also emphasises that nerve-sparing is a field under constant development, with new technologies entering continuously the nerve-sparing field corresponding to the evolving open, laparoscopic and robotic-assisted RP approaches.

Abstract

The purpose of this narrative review is to describe the different nerve-sparing techniques applied during radical prostatectomy and document their functional impact on postoperative outcomes. We performed a PubMed search of the literature using the keywords “nerve-sparing”, “techniques”, “prostatectomy” and “outcomes”. Other potentially eligible studies were retrieved using the reference list of the included studies. Nerve-sparing techniques can be distinguished based on the fascial planes of dissection (intrafascial, interfascial or extrafascial), the direction of dissection (retrograde or antegrade), the timing of the neurovascular bundle dissection off the prostate (early vs. late release), the use of cautery, the application of traction and the number of the neurovascular bundles which are preserved. Despite this rough categorisation, many techniques have been developed which cannot be integrated in one of the categories described above. Moreover, emerging technologies have entered the nerve-sparing field, making its future even more promising. Bilateral nerve-sparing of maximal extent, athermal dissection of the neurovascular bundles with avoidance of traction and utilization of the correct planes remain the basic principles for achieving optimum functional outcomes. Given that potency and continence outcomes after radical prostatectomy are multifactorial endpoints in addition to the difficulty in their postoperative assessment and the well-documented discrepancy existing in their definition, safe conclusions about the superiority of one technique over the other cannot be easily drawn. Further studies, comparing the different nerve-sparing techniques, are necessary.

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.

Anatomical Fundamentals and Current Surgical Knowledge of Prostate Anatomy Related to Functional and Oncological Outcomes for Robotic-Assisted Radical Prostatectomy

Context

Meticulous knowledge about the anatomy of the prostate and surrounding tissue represents a crucial and mandatory requirement during radical prostatectomy for reliable oncological and excellent replicable, functional outcomes. Since its introduction two decades ago, robotic-assisted laparoscopic radical prostatectomy (RALP) has evolved to become the predominant surgical approach in many industrialized countries.

Objective

To provide and highlight currently available literature regarding prostate anatomy and to help in improving oncological and functional outcomes in RALP.

Methods/Evidence Acquiring

PubMed database was searched using the following keywords: "robotic-assisted radical prostatectomy," "anatomy," "neurovascular bundle," "nerve," "periprostatic fascia," "pelvis," "sphincter," "urethra," "urinary incontinence," and "erectile dysfunction." Relevant articles and book chapters were critically reviewed and if eligible, they were included in this review.

Results

New evidence in regards to prostatic anatomy and surgical approaches in RALP has been reported in recent years. Besides detailed anatomical studies investigating the meticulous structure of the fascial structures surrounding the prostate and neurovascular bundle preservation, debate about the optimal RALP approach is still ongoing, inspired by recent publications presenting promising functional outcomes following modifications in surgical approaches.

Conclusions

This review provides a detailed overview of the current knowledge of prostate anatomy, its surrounding tissue, and its influence on key surgical step development for RALP.

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.