"Real-time" Assessment of Surgical Margins During Radical Prostatectomy: State-of-the-Art

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.

Rapid On-Site Microscopy and Mapping of Diagnostic Biopsies for See-And-Treat Guidance of Localized Prostate Cancer Therapy

Prostate cancer continues to be the most diagnosed non-skin malignancy in men. While up to one in eight men will be diagnosed in their lifetimes, most diagnoses are not fatal. Better lesion location accuracy combined with emerging localized treatment methods are increasingly being utilized as a treatment option to preserve healthy function in eligible patients. In locating lesions which are generally <2cc within a prostate (average size 45cc), small variance in MRI-determined boundaries, tumoral heterogeneity, patient characteristics including location of lesion and prostatic calcifications, and patient motion during the procedure can inhibit accurate sampling for diagnosis. The locations of biopsies are recorded and are then fully processed by histology and diagnosed via pathology, often days to weeks later. Utilization of real-time feedback could improve accuracy, potentially prevent repeat procedures, and allow patients to undergo treatment of clinically localized disease at earlier stages. Unfortunately, there is currently no reliable real-time feedback process for confirming diagnosis of biopsy samples. We examined the feasibility of implementing structured illumination microscopy (SIM) as a method for on-site diagnostic biopsy imaging to potentially combine the diagnostic and treatment appointments for prostate cancer patients, or to confirm tumoral margins for localized ablation procedures. We imaged biopsies from 39 patients undergoing image-guided diagnostic biopsy using a customized SIM system and a dual-color fluorescent hematoxylin & eosin (H&E) analog. The biopsy images had an average size of 342 megapixels (minimum 78.1, maximum 842) and an average imaging duration of 145 s (minimum 56, maximum 322). Comparison of urologist's suspicion of malignancy based on MRI, to pathologist diagnosis of biopsy images obtained in real time, reveals that real-time biopsy imaging could significantly improve confirmation of malignancy or tumoral margins over medical imaging alone.

Technical advances in nerve-sparing and continence preservation

PURPOSE OF REVIEW

Urinary incontinence and erectile dysfunction are common after radical prostatectomy. These side effects greatly impact patients' quality of life. Therefore, surgical techniques and technology tools are constantly being developed to optimize trifecta outcomes. Here we focus on advances in nerve-sparing (NS) and continence preservation.

RECENT FINDINGS

New surgical techniques dedicated to preservation rather than reconstruction have been developed to improve urinary continence (UC) and NS. On the other hand, intraoperative assessment of prostatic and periprostatic structures has shown promising outcomes toward NS whereas avoiding omission of extracapsular extension (ECE). Likewise, neural regeneration strategies are under research to improve return of erectile function and UC.

SUMMARY

Superb outcomes after Robot-Assisted Radical Prostatectomy require a proper balance between NS and risk of ECE. Detailed anatomic knowledge together with an accurate surgical planning are cornerstone for tailoring the approach in each case.

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.

The Use of Augmented Reality to Guide the Intraoperative Frozen Section During Robot-assisted Radical Prostatectomy

BACKGROUND

Multiparametric magnetic resonance imaging (mpMRI) can guide the surgical plan during robot-assisted radical prostatectomy (RARP), and intraoperative frozen section (IFS) can facilitate real-time surgical margin assessment.

OBJECTIVE

To assess a novel technique of IFS targeted to the index lesion by using augmented reality three-dimensional (AR-3D) models in patients scheduled for nerve-sparing RARP (NS-RARP).

DESIGN, SETTING, AND PARTICIPANTS

Between March 2019 and July 2019, 20 consecutive prostate cancer patients underwent NS-RARP with IFS directed to the index lesion with the help of AR-3D models (study group). Control group consists of 20 patients matched with 1:1 propensity score for age, clinical stage, Prostate Imaging Reporting and Data System score v2, International Society of Urological Pathology grade, prostate volume, NS approach, and prostate-specific antigen in which RARP was performed by cognitive assessment of mpMRI.

SURGICAL PROCEDURE

In the study group, an AR-3D model was superimposed to the surgical field to guide the surgical dissection. Tissue sampling for IFS was taken in the area in which the index lesion was projected by AR-3D guidance.

MEASUREMENTS

Chi-square test, Student t test, and Mann-Whitney U test were used to compare, respectively, proportions, means, and medians between the two groups.

RESULTS AND LIMITATIONS

Patients in the AR-3D group had comparable preoperative characteristics and those undergoing the NS approach were referred to as the control group (all p ≥ 0.06). Overall, positive surgical margin (PSM) rates were comparable between the two groups; PSMs at the level of the index lesion were significantly lower in patients referred to AR-3D guided IFS to the index lesion (5%) than those in the control group (20%; p = 0.01).

CONCLUSIONS

The novel technique of AR-3D guidance for IFS analysis may allow for reducing PSMs at the level of the index lesion.

PATIENT SUMMARY

Augmented reality three-dimensional guidance for intraoperative frozen section analysis during robot-assisted radical prostatectomy facilitates the real-time assessment of surgical margins and may reduce positive surgical margins at the index lesion.

Intraoperative pathology consultation during urological surgery: Impact on final margin status and pitfalls of frozen section diagnosis

Despite recent improvements in diagnostic and surgical techniques in urological oncology, positive resection margin remains a significant concern for surgeons. Meanwhile, intraoperative pathology consultation with frozen section assessment (FSA), particularly for histological diagnosis of the lesions incidentally found or enlarged or sentinel lymph nodes, generally provides critical information which enables immediate decision making for optimal patient care. The intraoperative evaluation of surgical margins is also often requested, although there are some differences in its application between institutions and surgeons. Importantly, it remains to be determined whether intraoperative FSA indeed contributes to reducing the risk of final positive margins and thereby improving long-term patient outcomes. This review summarizes available data indicating the potential impact of FSA at the surgical margins during urological surgeries, including radical or partial cystectomy, partial nephrectomy, radical prostatectomy, penectomy, and orchiectomy. The accuracy and pitfalls of the intraoperative consultation/FSA diagnosis are also discussed.

Evaluation of Oncological Outcomes and Data Quality in Studies Assessing Nerve-sparing Versus Non-Nerve-sparing Radical Prostatectomy in Nonmetastatic Prostate Cancer: A Systematic Review

CONTEXT

Surgical techniques aimed at preserving the neurovascular bundles during radical prostatectomy (RP) have been proposed to improve functional outcomes. However, it remains unclear if nerve-sparing (NS) surgery adversely affects oncological metrics.

OBJECTIVE

To explore the oncological safety of NS versus non-NS (NNS) surgery and to identify factors affecting the oncological outcomes of NS surgery.

EVIDENCE ACQUISITION

Relevant databases were searched for English language articles published between January 1, 1990 and May 8, 2020. Comparative studies for patients with nonmetastatic prostate cancer (PCa) treated with primary RP were included. NS and NNS techniques were compared. The main outcomes were side-specific positive surgical margins (ssPSM) and biochemical recurrence (BCR). Risk of bias (RoB) and confounding assessments were performed.

EVIDENCE SYNTHESIS

Out of 1573 articles identified, 18 studies recruiting a total of 21 654 patients were included. The overall RoB and confounding were high across all domains. The most common selection criteria for NS RP identified were characteristic of low-risk disease, including low core-biopsy involvement. Seven studies evaluated the link with ssPSM and showed an increase in ssPSM after adjustment for side-specific confounders, with the relative risk for NS RP ranging from 1.50 to 1.53. Thirteen papers assessing BCR showed no difference in outcomes with at least 12 mo of follow-up. Lack of data prevented any subgroup analysis for potentially important variables. The definitions of NS were heterogeneous and poorly described in most studies.

CONCLUSIONS

Current data revealed an association between NS surgery and an increase in the risk of ssPSM. This did not translate into a negative impact on BCR, although follow-up was short and many men harbored low-risk PCa. There are significant knowledge gaps in terms of how various patient, disease, and surgical factors affect outcomes. Adequately powered and well-designed prospective trials and cohort studies accounting for these issues with long-term follow-up are recommended.

PATIENT SUMMARY

Neurovascular bundles (NVBs) are structures containing nerves and blood vessels. The NVBs close to the prostate are responsible for erections. We reviewed the literature to determine if a technique to preserve the NVBs during removal of the prostate causes worse cancer outcomes. We found that NVB preservation was poorly defined but, if applied, was associated with a higher risk of cancer at the margins of the tissue removed, even in patients with low-risk prostate cancer. The long-term importance of this finding for patients is unclear. More data are needed to provide recommendations.

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Current and future perspectives of digital microscopy with fluorescence confocal microscope for prostate tissue interpretation: a narrative review

Fluorescence confocal microscopy (FCM) is an optical imaging technique providing digital microscopical images of fresh tissue in a real time fashion, without conventional processing. FCM has been widely applied in several fields of dermatology, including the detection of basal cell carcinoma and of cutaneous inflammatory diseases. The aim of the paper is to provide an overview of FCM applications in the field of prostate tissue interpretation and prostate cancer (PCa) detection. A Literature search (PubMed & Web of Science) was performed to identify articles concerned with the clinical and surgical applications of FCM in prostatic and periprostatic tissues interpretation. Overall, six articles were identified. All articles investigated the level of agreement between FCM and conventional histopathological analysis (hematoxylin-eosin, HE) for the discrimination between normal and PCa tissues. An investigative article on prostate samples retrieved from radical prostatectomy (RP) specimens and an atlas of FCM digital images from the same series were found. Two prospective clinical trials, comparing FCM and HE, pointed out a “substantial” to “almost perfect” discriminative performance of FCM for the diagnosis of PCa on prostate biopsy core. Finally, two studies investigated the intra-operative role of FCM during RP for the control of surgical dissection. In this setting, FCM could be used to analyse samples retrieved from suspicious peri-prostatic areas; FCM has also been tested for an en-face evaluation of flat slices obtained from the systematic sampling of the posterolateral aspects of the prostate, in a NeuroSAFE-like approach. Generally, FCM provides digital microscopical images of fresh tissue in a real time fashion, without requiring conventional processing. Currently, available studies confirmed a high concordance with conventional pathology for the detection of PCa. Further studies are required to validate the technology, to evaluate ISUP score attribution and to implement the fields of application of FCM for the treatment of prostate diseases.

Ratiometric Fluorescence Imaging for the Distribution of Nucleic Acid Content in Living Cells and Human Tissue Sections

The misregulation of nucleic acids behavior leads to cell dysfunction and induces serious diseases. A ratiometric fluorescence probe is a powerful tool to study the dynamic behavior and function relationships of nucleic acids. However, currently, no such effective probe has been reported for in situ, real-time tracking of nucleic acids in living cells and tissue sections. Herein, the unique probe named QPP-AS was rationally designed for ratiometric fluorescence response to nucleic acids through skillful regulation of the intramolecular charge-transfer capabilities of the electron acceptor and donor. Encouraged by the advantages of the selective nucleic acid response, ideal biocompatibility, and high signal-to-noise ratio, QPP-AS has been applied for in situ, real-time ratiometric fluorescence imaging of nucleic acids in living cells for the first time. Furthermore, we have demonstrated that QPP-AS is capable of visualizing the dynamic behavior of nucleic acids during different cellular processes (e.g., cell division and apoptosis) by ratiometric fluorescence imaging. More significantly, QPP-AS has been successfully used for ratiometric fluorescence imaging of nucleic acids in human tissue sections, which provides not only the cell contour, nuclear morphology, and nuclear-plasma ratio but also the nucleic acid content information and may greatly improve accuracy in clinicopathological diagnosis.

Real-time Augmented Reality Three-dimensional Guided Robotic Radical Prostatectomy: Preliminary Experience and Evaluation of the Impact on Surgical Planning

BACKGROUND

Augmented reality (AR) is a novel technology adopted in prostatic surgery.

OBJECTIVE

To evaluate the impact of a 3D model with AR (AR-3D model), to guide nerve sparing (NS) during robot-assisted radical prostatectomy (RARP), on surgical planning.

DESIGN, SETTING, AND PARTICIPANTS

Twenty-six consecutive patients with diagnosis of prostate cancer (PCa) and multiparametric magnetic resonance imaging (mpMRI) results available were scheduled for AR-3D NS RARP.

INTERVENTION

Segmentation of mpMRI and creation of 3D virtual models were achieved. To develop AR guidance, the surgical DaVinci video stream was sent to an AR-dedicated personal computer, and the 3D virtual model was superimposed and manipulated in real time on the robotic console.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The concordance of localisation of the index lesion between the 3D model and the pathological specimen was evaluated using a prostate map of 32 specific areas. A preliminary surgical plan to determinate the extent of the NS approach was recorded based on mpMRI. The final surgical plan was reassessed during surgery by implementation of the AR-3D model guidance.

RESULTS AND LIMITATIONS

The positive surgical margin (PSM) rate was 15.4% in the overall patient population; three patients (11.5%) had PSMs at the level of the index lesion. AR-3D technology changed the NS surgical plan in 38.5% of men on patient-based and in 34.6% of sides on side-based analysis, resulting in overall appropriateness of 94.4%. The 3D model revealed 70%, 100%, and 92% of sensitivity, specificity, and accuracy, respectively, at the 32-area map analysis.

CONCLUSIONS

AR-3D guided surgery is useful for improving the real-time identification of the index lesion and allows changing of the NS approach in approximately one out of three cases, with overall appropriateness of 94.4%.

PATIENT SUMMARY

Augmented reality three-dimensional guided robot-assisted radical prostatectomy allows identification of the index prostate cancer during surgery, to tailor the surgical dissection to the index lesion and to change the extent of nerve-sparing dissection.

The Role of Stereotactic Biopsy in Brain Metastases

Brain metastases (BrM) affect up to 20% of patients with cancer and represent an increasing portion of patients with surgical brain tumors owing to improving prognoses of cancer patients in general and in many cases even of those with brain metastases. With advances in molecular biology and targeted therapy, the indications for neurosurgical sampling and specifically stereotactic biopsy are likely to change in the future. In this review the authors address some of the scientific advances in BrM biology, the clinical rationale and range of techniques currently used to perform stereotactic biopsy, and how the advent of molecular interrogation may potentially alter the way patients with BrM are managed in the future.