Three-dimensional Elastic Augmented-reality Robot-assisted Radical Prostatectomy Using Hyperaccuracy Three-dimensional Reconstruction Technology: A Step Further in the Identification of Capsular Involvement

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 Use of Three-dimensional Visualization Techniques for Prostate Procedures: A Systematic Review

CONTEXT

As an emerging technique, three-dimensional (3D) visualization has become more popular and can facilitate education, training, surgical planning, and intraoperative guidance for prostate cancer surgery.

OBJECTIVE

In this review, we aim to present the impact of 3D printing, virtual reality (VR), and augmented reality (AR) techniques for prostate cancer procedures, specifically prostate biopsy and radical prostatectomy (RP).

EVIDENCE ACQUISITION

A systematic review was performed by two investigators according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria.

EVIDENCE SYNTHESIS

A total of 541 papers were identified in PubMed, Scopus, and Embase. Of these, 53 studies were identified for detailed review and 25 were qualified. Two more studies were identified from the references; thus, 27 studies were finally included in this systematic review. Nine papers reported on the use of 3D reconstructed models, mainly in education/training and intraoperative guidance; nine reported on VR, focusing on simulation training model and intraoperative guidance; and nine reported on AR technique with its best indication for surgical guidance in robotic RP.

CONCLUSIONS

Three-dimensional visualization techniques have gradually been introduced and developed in prostate procedures, and demonstrate potential utility not only for education/training, but also for surgical planning and intraoperative guidance. Prospective studies are needed to demonstrate clinical utility and validation of these technologies.

PATIENT SUMMARY

Despite low-quality evidence, promising signals were identified to demonstrate that three-dimensional visualization could help facilitate prostate procedures, in terms of education/training, surgical planning, and intraoperative guidance. It is still in a very early stage, and more studies need to be conducted to justify its widespread use.

Variability in accuracy of prostate cancer segmentation among radiologists, urologists, and scientists

Background

There is increasing research in using segmentation of prostate cancer to create a digital 3D model from magnetic resonance imaging (MRI) scans for purposes of education or surgical planning. However, the variation in segmentation of prostate cancer among users and potential inaccuracy has not been studied.

Methods

Four consultant radiologists, four consultant urologists, four urology trainees, and four nonclinician segmentation scientists were asked to segment a single slice of a lateral T3 prostate tumor on MRI (“Prostate 1”), an anterior zone prostate tumor MRI (“Prostate 2”), and a kidney tumor computed tomography (CT) scan (“Kidney”). Time taken and self‐rated subjective accuracy out of a maximum score of 10 were recorded. Root mean square error, Dice coefficient, Matthews correlation coefficient, Jaccard index, specificity, and sensitivity were calculated using the radiologists as the ground truth.

Results

There was high variance among the radiologists in segmentation of Prostate 1 and 2 tumors with mean Dice coefficients of 0.81 and 0.58, respectively, compared to 0.96 for the kidney tumor. Urologists and urology trainees had similar accuracy, while nonclinicians had the lowest accuracy scores for Prostate 1 and 2 tumors (0.60 and 0.47) but similar for kidney tumor (0.95). Mean sensitivity in Prostate 1 (0.63) and Prostate 2 (0.61) was lower than specificity (0.92 and 0.93) suggesting under‐segmentation of tumors in the non‐radiologist groups. Participants spent less time on the kidney tumor segmentation and self‐rated accuracy was higher than both prostate tumors.

Conclusion

Segmentation of prostate cancers is more difficult than other anatomy such as kidney tumors. Less experienced participants appear to under‐segment models and underestimate the size of prostate tumors. Segmentation of prostate cancer is highly variable even among radiologists, and 3D modeling for clinical use must be performed with caution. Further work to develop a methodology to maximize segmentation accuracy is needed.

3D augmentation of the surgical video stream: Toward a modular approach

BACKGROUND AND OBJECTIVE

We present an original approach to the development of augmented reality (AR) real-time solutions for robotic surgery navigation. The surgeon operating the robotic system through a console and a visor experiences reduced awareness of the operatory scene. In order to improve the surgeon's spatial perception during robot-assisted minimally invasive procedures, we provide him/her with a solid automatic software system to position, rotate and scale in real-time the 3D virtual model of a patient's organ aligned over its image captured by the endoscope.

METHODS

We observed that the surgeon may benefit differently from the 3D augmentation during each stage of the surgical procedure; moreover, each stage may present different visual elements that provide specific challenges and opportunities to exploit for organ detection strategies implementation. Hence we integrate different solutions, each dedicated to a specific stage of the surgical procedure, into a single software system.

RESULTS

We present a formal model that generalizes our approach, describing a system composed of integrated solutions for AR in robot-assisted surgery. Following the proposed framework, and application has been developed which is currently used during in vivo surgery, for extensive testing, by the Urology unity of the San Luigi Hospital, in Orbassano (To), Italy.

CONCLUSIONS

The main contribution of this paper is in presenting a modular approach to the tracking problem during in-vivo robotic surgery, whose efficacy from a medical point of view has been assessed in cited works. The segmentation of the whole procedure in a set of stages allows associating the best tracking strategy to each of them, as well as to re-utilize implemented software mechanisms in stages with similar features.

Cutting-edge Management of Muscle-invasive Bladder Cancer in 2020 and a Glimpse into the Future

This case-based discussion describes the clinical course of a 63-yr-old patient who presented with gross hematuria and was diagnosed with a muscle-invasive bladder cancer at transurethral resection. Computed tomography revealed a locally advanced tumor, and the patient underwent neoadjuvant chemotherapy followed by open radical cystectomy with standard pelvic lymph node dissection. In a step-by-step fashion, we elaborate on diagnostic and therapeutic treatment options from two different vantage points: (1) guideline-adherent treatment with the state-of-the-art standard of care, and (2) a glimpse into the future discussing the evidence of potential additional or alternative approaches based on recent scientific advances. PATIENT SUMMARY: In this case-based discussion, we follow the clinical course of a patient with advanced bladder cancer and elaborate how the state-of-the-art treatment looks like in 2020, based on the best available evidence. This is compared with potential future treatment strategies, which may change and alternate our understanding of optimal bladder cancer care.

Techniques of robotic radical prostatectomy for the management of prostate cancer: which one, when and why

The advent of robotic assistance in surgery has completely revolutionized the surgical management of prostate cancer. It enables precise dissection and reconstruction in order to maximize oncological and functional outcomes. In many parts of the world, robot-assisted laparoscopic radical prostatectomy has evolved to become the surgical standard of care for localized disease, including in appropriately selected patients with high risk prostate cancer. Its role has also been expanded to encompass cytoreductive prostatectomy and salvage radical prostatectomy. As surgical expertise grows with robotic assistance, several novel and non-radical approaches have been developed to further mitigate treatment side effects. Patient characteristics, disease factors and surgeon expertise are important metrics for consideration when selecting the most appropriate technique for any given patient.

Current Status of Simulation Training in Urology: A Non-Systematic Review

Simulation has emerged as an effective solution to increasing modern constraints in surgical training. It is recognized that a larger proportion of surgical complications occur during the surgeon's initial learning curve. The simulation takes the learning curve out of the operating theatre and facilitates training in a safe and pressure-free environment whilst focusing on patient safety. The cost of simulation is not insignificant and requires commitment in funding, human resources and logistics. It is therefore important for trainers to have evidence when selecting various simulators or devices. Our non-systematic review aims to provide a comprehensive up-to-date picture on urology simulators and the evidence for their validity. It also discusses emerging technologies and future directions. Urologists should embed evidence-based simulation in training programs to shorten learning curves while maintaining patient safety and work should be directed toward a validated and agreed curriculum.

Positive surgical margin during radical prostatectomy: overview of sampling methods for frozen sections and techniques for the secondary resection of the neurovascular bundles

OBJECTIVE

The aim of the paper is to provide an overview of intraoperative sampling methods for frozen section (FS) analysis and of surgical techniques for a secondary neurovascular bundle (NVB) resection, as the method of surgical margin (SM) sampling and the management of a positive SM (PSM) at the nerve-sparing (NS) area are under evaluated issues. FS analysis during radical prostatectomy (RP) can help to tailor the plane of dissection based on cancer extension and thus extend the indications for NS surgery.

EVIDENCE ACQUISITION

We performed a PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE), Web of Science, Cochrane Library, and Elton B. Stephens Co. (EBSCO)host search to include articles published in the last decade, evaluating FS analysis in the NS area and surgical attempts to convert a PSM to a negative status.

EVIDENCE SYNTHESIS

Overall, 19 papers met our inclusion criteria. The ways to collect samples for FS analysis included: systematic (analysing the whole posterolateral aspect of the prostate specimen, i.e., neurovascular structure-adjacent frozen-section examination [NeuroSAFE]); magnetic resonance imaging (MRI)-guided (biopsies from MRI-suspicious areas, retrieved by the surgeon in a cognitive way); and random biopsies from the soft periprostatic tissues. Techniques to address a PSM in the NS area included: full resection of the spared NVB, from its caudal to cranial aspect, often including the rectolateral part of the Denonvilliers' fascia; partial resection of the NVB, in cases where sampling attempts to localise a PSM; incremental approach, meaning a partial or full resection that extends until no prostate tissue is found in the soft periprostatic environment.

CONCLUSIONS

There is no homogeneity in prostate sampling for FS analysis, although most recent evidence is moving toward a systematic sampling of the entire NS area. The management of a PSM is variable and can be affected by the sampling strategy (difficult localisation of the persisting tumour at the NVB). The difficult identification of the exact soft tissue location contiguous to a PSM could be considered as the critical point of FS analysis and of spared-NVB management.

Three-dimensional Augmented Reality Robot-assisted Partial Nephrectomy in Case of Complex Tumours (PADUA ≥10): A New Intraoperative Tool Overcoming the Ultrasound Guidance

BACKGROUND

Despite technical improvements introduced with robotic surgery, management of complex tumours (PADUA score ≥10) is still a matter of debate within the field of transperitoneal robot-assisted partial nephrectomy (RAPN).

OBJECTIVE

To evaluate the accuracy of our three-dimensional (3D) static and elastic augmented reality (AR) systems based on hyperaccuracy models (HA3D) in identifying tumours and intrarenal structures during transperitoneal RAPN (AR-RAPN), compared with standard ultrasound (US).

DESIGN, SETTING, AND PARTICIPANTS

A retrospective study was conducted, including 91 patients who underwent RAPN for complex renal tumours, 48 with 3D AR guidance and 43 with 2D US guidance, from July 2017 to May 2019.

SURGICAL PROCEDURE

In patients who underwent 3D AR-RAPN, virtual image overlapping guided the surgeon during resection and suture phases. In the 2D US group, interventions were driven by US only.

MEASUREMENTS

Patient characteristics were tested using the Fisher's exact test for categorical variables and the Mann-Whitney test for continuous ones. Intraoperative, postoperative, and surgical outcomes were collected. All results for continuous variables were expressed as medians (range), and frequencies and proportions were reported as percentages.

RESULTS AND LIMITATIONS

The use of 3D AR guidance makes it possible to correctly identify the lesion and intraparenchymal structures with a more accurate 3D perception of the location and the nature of the different structures relative to the standard 2D US guidance. This translates to a lower rate of global ischaemia (45.8% in the 3D group vs 69.7% in the US group; p = 0.03), higher rate of enucleation (62.5% vs 37.5% in the 3D and US groups, respectively; p = 0.02), and lower rate of collecting system violation (10.4% vs 45.5%; p = 0.003). Postoperatively, 3D AR guidance use correlates to a low risk of surgery-related complications in 3D AR groups and a lower drop in estimated renal plasma flow at renal scan at 3 mo of follow-up (-12.38 in the 3D group vs -18.14 in the US group; p = 0.01). The main limitations of this study are short follow-up time and small sample size.

CONCLUSIONS

HA3D models that overlap in vivo anatomy during AR-RAPN for complex tumours can be useful for identifying the lesion and intraparenchymal structures that are difficult to visualise with US only. This translates to a potential improvement in the quality of the resection phase and a reduction in postoperative complications, with better functional recovery.

PATIENT SUMMARY

Based on our findings, three-dimensional augmented reality robot-assisted partial nephrectomy seems to help surgeons in the management of complex renal tumours, with potential early postoperative benefits.

Advanced Reconstruction of Vesicourethral Support (ARVUS) during robot-assisted radical prostatectomy: first independent evaluation and review of other factors influencing 1 year continence outcomes

PURPOSE

Anterior and posterior reconstructions of pelvic structures are used during a robot-assisted radical prostatectomy to obtain better continence outcomes. This study was conducted to evaluate the Advanced Reconstruction of Vesicourethral Support (ARVUS), a novel postprostatectomy reconstruction technique.

METHODS

The study was designed as a prospective, controlled, partially randomized and blinded experiment. The statistical analysis was based on the generalized linear modeling (GLM) framework with random effects: the logit link was used to model the probability of achieving continence and the logarithmic link was used to evaluate the overall score of the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). The significance of the fixed effects and all possible two-way interactions was tested using the critical level of 0.05.

RESULTS

The probability of achieving the continence significantly depends on the neurovascular bundle sparing (p < 0.001) and the time after the surgery (p < 0.001). Analogously, the expected ICIQ-SF score significantly depends on the nerve-sparing status (p = 0.035) and the time after the surgery (p < 0.001). No statistically significant difference between the unilateral or bilateral nerve sparing was found. The ARVUS technique seems to perform slightly worse with respect to the expected continence, but this difference is within the margins of random fluctuations (p = 0.715).

CONCLUSIONS

The study demonstrates a significant positive association between the nerve-sparing approach and the patient's continence, however, regardless of the unilateral or bilateral approach. In terms of the continence rate, no statistically significant benefits of ARVUS were observed.

Climbing over the Barriers of Current Imaging Technology in Urology

We are facing an era of disruption in the field of anatomic visualisation. The future standard in urology will probably emerge from among several possibilities that are outlined here.