Can preoperative planning using IRIS™ three-dimensional anatomical virtual models predict operative findings during robot-assisted partial nephrectomy?

Objective: To evaluate the predictive validity of IRIS™ (Intuitive Surgical®, Sunnyvale, CA, USA) as a planning tool for robot-assisted partial nephrectomy (RAPN) by assessing the degree of overlap with intraoperative execution. Methods: Thirty-one patients scheduled for RAPN by four experienced urologists were enrolled in a prospective study. Prior to surgery, urologists reviewed the IRIS™ three-dimensional model on an iphone Operating System (iOS) app and completed a questionnaire outlining their surgical plan including surgical approach, and ischemia technique as well as confidence in executing this plan. Postoperatively, questionnaires assessing the procedural approach, clinical utility, efficiency, and effectiveness of IRIS™ were completed. The degree of overlap between the preoperative and intraoperative questionnaires and between the planned approach and actual execution of the procedure was analyzed. Questionnaires were answered on a 5-point Likert scale and scores of 4 or greater were considered positive. Results: Mean age was 65.1 years with a mean tumor size of 27.7 mm (interquartile range 17.5-44.0 mm). Hilar tumors consisted of 32.3%; 48.4% of patients had R.E.N.A.L. nephrometry scores of 7-9. On preoperative questionnaires, the surgeons reported that in 67.7% cases they were confident that they can perform the procedure successfully, and on intraoperative questionnaires, the surgeons reported that in 96.8% cases IRIS™ helped achieve good spatial sensation of the anatomy. There was a high degree of overlap between preoperative and intraoperative questionnaires for the surgical approach, interpreting anatomical details and clinical utility. When comparing plans for selective or off-clamp, the preoperative plan was executed in 90.0% of cases intraoperatively. Conclusion: A high degree of overlap between the preoperative surgical approach and intraoperative RAPN execution was found using IRIS™. This is the first study to evaluate the predictive accuracy of IRIS™ during RAPN by comparing preoperative plan and intraoperative execution.

Role of multi-parametric magnetic resonance imaging fusion biopsy in active surveillance of prostate cancer: a systematic review.

Background: Our goal is to review current literature regarding the role of multi-parametric magnetic resonance imaging (mpMRI) in the active surveillance (AS) of prostate cancer (PCa) and identify trends in rate of reclassification of risk category, performance of fusion biopsy (FB) versus systematic biopsy (SB), and progression-free survival. Methods: We performed a comprehensive literature search in PubMed and identified 121 articles. A narrative summary was performed. Results: Thirty-two articles were chosen to be featured in this review. SB and FB are complementary in detecting higher-grade disease in follow-up. While FB was more likely than SB to detect clinically significant disease, FB missed 6.4-11% of clinically significant disease. Imaging factors that predicted upgrading include number of lesions on magnetic resonance imaging (MRI), lesion density, and MRI suspicion level. Conclusion: Incorporating mpMRI FB in conjunction with SB should be part of contemporary AS protocols. mpMRI should additionally be used routinely for follow-up; however, mpMRI is not currently sensitive enough in detecting disease progression to replace biopsy in the surveillance protocol.

Utilizing head-mounted eye trackers to analyze patterns and decision-making strategies of 3D virtual modelling platform (IRIS™) during preoperative planning for renal cancer surgeries.

PURPOSE: IRIS™ provides interactive, 3D anatomical visualizations of renal anatomy for pre-operative planning that can be manipulated by altering transparency, rotating, zooming, panning, and overlaying the CT scan. Our objective was to analyze how eye tracking metrics and utilization patterns differ between preoperative surgical planning of renal masses using IRIS and CT scans. METHODS: Seven surgeons randomly reviewed IRIS and CT images of 9 patients with renal masses [5 high complexity (RENAL score ≥ 8), 4 low complexity (≤ 7)]. Surgeons answered a series of questions regarding patient anatomy, perceived difficulty (/100), confidence (/100), and surgical plan. Eye tracking metrics (mean pupil diameter, number of fixations, and gaze duration) were collected. RESULTS: Surgeons spent significantly less time interpreting data from IRIS than CT scans (- 67.1 s, p < 0.01) and had higher inter-rater agreement of surgical approach after viewing IRIS (α = 0.16-0.34). After viewing IRIS, surgical plans although not statistically significant demonstrated a greater tendency towards a more selective ischemia approaches which positively correlated with improved identification of vascular anatomy. Planned surgical approach changed in 22/59 of the cases. Compared to viewing the CT scan, left and right mean pupil diameter and number/duration of fixations were significantly lower when using IRIS (p < 0.01, p < 0.01, p = 0.42, p < 0.01, respectively), indicating interpreting information from IRIS required less mental effort despite under-utilizing its interactive features. CONCLUSIONS: Surgeons extrapolated more detailed information in less time with less mental effort using IRIS than CT scans and proposed surgical approaches with potential to enhanced surgical outcomes.

Comparison of Multi-Parametric MRI of the Prostate to 3D Prostate Computer Aided Designs and 3D-Printed Prostate Models for Pre-Operative Planning of Radical Prostatectomies: A Pilot Study.

OBJECTIVE: To evaluate the use of 3D computed aided designs and 3D-printed models as pre-operative planning tools for urologists, in addition to radiologist interpreted mp-MRIS, prior to radical prostatectomy procedures. METHODS: Ten patients with biopsy-positive lesions detected on mp-MRI were retrospectively selected. Radiologists identified lesion locations using a Prostate Imaging-Reporting and Data System (PI-RADS) map and segmented the prostate, lesion(s), and surrounding anatomy to create 3D-CADs and 3D-printed models for each patient. 6 uro-oncologists randomly reviewed three modalities (mp-MRI, 3D-CAD, and 3D-printed models) for each patient and identified lesion locations which were graded for accuracy against the radiologists' answers. Questionnaires assessed decision confidence, ease-of-interpretation, and usefulness for preoperative planning for each modality. RESULTS: Using 3D-CADs and 3D-printed models compared to mp-MRI, urologists were 2.4x and 2.8x more accurate at identifying the lesion(s), 2.7x and 3.2x faster, 1.6x and 1.63x more confident, and reported it was 1.6x and 1.7x easier to interpret. 3D-CADs and 3D-printed models were reported significantly more useful for overall pre-operative planning, identifying lesion location(s), determining degree of nerve sparing, obtaining negative margins, and patient counseling. Sub-analysis showed 3D-printed models demonstrated significant improvements in ease-of-interpretation, speed, usefulness for obtaining negative margins, and patient counseling compared to 3D-CADs. CONCLUSION: 3D-CADs and 3D-printed models are useful adjuncts to mp-MRI in providing urologists with more practical, accurate, and efficient pre-operative planning.

Application of IRIS Three-Dimensional Anatomical Models As Preoperative Surgical Planning Tools in the Management of Localized Renal Masses.

Introduction: The use of volume-rendered images is gaining popularity in the surgical planning for complex procedures. IRIS™ is an interactive software that delivers three-dimensional (3D) virtual anatomical models. We aimed to evaluate the preoperative clinical utility of IRIS for patients with ≤T2 localized renal tumors who underwent either partial nephrectomy (PN) or radical nephrectomy (RN). Patients and Methods: Six urologists (four faculty and two trainees) reviewed CT scans of 40 cases over 2 study phases, using conventional two-dimensional (2D) CT alone (Phase-I), followed by the CT + IRIS 3D model (Phase-II). After each review, surgeons reported their decision on performing a PN or an RN and rated (Likert scale) their confidence in completing the procedure as well as how the imaging modality influenced specific procedural decisions. Modifications to the choice of procedure and confidence in decisions between both phases were compared for the same surgeon. Concordance between surgeons was also evaluated. Results: A total of 462 reviews were included in the analysis (231 in each phase). In 64% (95% CI: 58-70%) of reviews, surgeons reported that IRIS achieved a better spatial orientation, understanding of the anatomy, and offered additional information compared with 2D CT alone. IRIS impacted the planned procedure in 20% of the reviews (3.5% changed decision from PN to RN and 16.5% changed from RN to PN). In the remaining 80% of reviews, surgeons' confidence increased from 78% (95% CI: 72-84%) with 2D CT, to 87% (95% CI: 82-92%) with IRIS (p = 0.02); this confidence change was more pronounced in cases with a high RENAL score (p = 0.009). In 99% of the reviews, surgeons rated that the IRIS accurately represented the anatomical details of all kidney components. Conclusion: Application of IRIS 3D models could influence the surgical decision-making process and improve surgeons' confidence, especially for robot-assisted management of complex renal tumors.

Robot-assisted Synchronous Bilateral Nephrectomy for Autosomal Dominant Polycystic Kidney Disease: A Stepwise Description of Technique.

OBJECTIVE: To describe our technique of robot-assisted synchronous bilateral nephrectomy (RASBN) for autosomal dominant polycystic kidney disease (ADPKD). METHODS: Given prior abdominal surgery/transplant in most patients, we prefer an open cut-down access to place a 12 mm port 10 cm infraumbilically. Four (8 mm) robotic ports are then placed under vision in a fan distribution along the umbilical level. The operating table is placed in reverse Trendelenburg and tilted opposite to the targeted side. Provided there are no concerns for malignancy, some cysts encountered in large kidneys (>2.5 L) may require puncture, to facilitate access and mobilization. The resected kidney is placed in a large bag and tucked in the pelvis. A similar procedure is carried out on the contralateral side after redocking the robot and tilting the table in the opposite direction. The specimen bags are extracted by elongating the lower midline 12 mm port site. RESULTS: Seven cases of RASBN performed for ADPKD were identified (December 2015 to December 2018). Median (interquartile range, IQR) values for patient demographics were: Age = 59 years (47-63), body mass index = 29 (26-32), and American Society of Anaesthesiology grade = 3. Three patients had prior deceased- and 4 had prior living- donor transplants. Indication for nephrectomy were: pain (5), hemorrhage into cysts (3), and renal masses (2). Perioperative outcomes were: operating room time = 388 minutes, estimated blood loss = 200 mL, hemoglobin change = 1.3 g/dL, transfusion = 0, length of hospital stay = 3 days, Grade I Clavien-Dindo complications = 2 cases. All patients were alive at a median follow-up of 3.8 years. CONCLUSION: RASBN is safe and effective in ADPKD even in the context of prior renal transplant patients with attendant comorbidities.

Multi-institutional validation of a perfused robot-assisted partial nephrectomy procedural simulation platform utilizing clinically relevant objective metrics of simulators (CROMS).

OBJECTIVE: To conduct a multi-institutional validation of a high-fidelity, perfused, inanimate, simulation platform for robot-assisted partial nephrectomy (RAPN) using incorporated clinically relevant objective metrics of simulation (CROMS), applying modern validity standards. MATERIALS AND METHODS: Using a combination of three-dimensional (3D) printing and hydrogel casting, a RAPN model was developed from the computed tomography scan of a patient with a 4.2-cm, upper-pole renal tumour (RENAL nephrometry score 7×). 3D-printed casts designed from the patient's imaging were used to fabricate and register hydrogel (polyvinyl alcohol) components of the kidney, including the vascular and pelvicalyceal systems. After mechanical and anatomical verification of the kidney phantom, it was surrounded by other relevant hydrogel organs and placed in a laparoscopic trainer. Twenty-seven novice and 16 expert urologists, categorized according to caseload, from five academic institutions completed the simulation. RESULTS: Clinically relevant objective metrics of simulators, operative complications, and objective performance ratings (Global Evaluative Assessment of Robotic Skills [GEARS]) were compared between groups using Wilcoxon rank-sum (continuous variables) and parametric chi-squared (categorical variables) tests. Pearson and point-biserial correlation coefficients were used to correlate GEARS scores to each CROMS variable. Post-simulation questionnaires were used to obtain subjective supplementation of realism ratings and training effectiveness. RESULTS: Expert ratings demonstrated the model's superiority to other procedural simulations in replicating procedural steps, bleeding, tissue texture and appearance. A significant difference between groups was demonstrated in CROMS [console time (P < 0.001), warm ischaemia time (P < 0.001), estimated blood loss (P < 0.001)] and GEARS (P < 0.001). Six major intra-operative complications occurred only in novice simulations. GEARS scores highly correlated with the CROMS. CONCLUSIONS: This perfused, procedural model offers an unprecedented realistic simulation platform, which incorporates objective, clinically relevant and procedure-specific performance metrics.

Cribriform pattern and perineural invasion on MR/US fusion biopsy predict failure of selection criteria for prostatic hemigland ablation.

OBJECTIVES: To assess clinicopathologic factors on MR/US fusion biopsy that might predict failure of theoretical selection criteria for prostatic hemigland ablation (HA). SUBJECTS AND METHODS: A retrospectively maintained single institution multiparametric MRI database (n = 1667) was queried to identify 355 patients who underwent MR/US fusion biopsy, including both targeted biopsy and concurrent systematic biopsy from December 1, 2014 to June 1, 2018. Clinical, pathological, and imaging variables were assessed on fusion biopsy (Table 1) to determine who met theoretical selection criteria for HA, defined as unilateral intermediate-risk prostate cancer per NCCN criteria (Grade Group [GG] 2 or 3 with prostate-specific antigen <20) and no evidence of extraprostatic extension (EPE) on multiparametric MRI. Predictors of selection criteria failure were then assessed in patients who also underwent radical prostatectomy (RP). Failure of the theoretical HA selection criteria was defined as presence of GG ≧ 2 on the contralateral (untreated) side, or the presence of high-risk disease (any GG ≧ 4 or EPE) in the RP specimen. RESULTS: Of the 355 patients who underwent fusion biopsy, 84 patients met the theoretical selection criteria for HA. Of those patients eligible, 54 underwent RP, 37 (68.5%) of which represented unsuccessful HA selection criteria. Patients no longer met HA selection criteria on the basis of upgrading alone in 6/54 (11.1%), EPE alone in 9/54 (16.7%), bilateral GG 2 or 3 in 16/54 (29.6%) or combined EPE and bilateral GG 2 or 3 in 6/54 (11.1%) cases. In the HA selection failures due to upgrading, three also had EPE, one of whom also had missed contralateral GG ≧ 2 disease. The only factor independently associated with HA failure was any presence of cribriform pattern (HR 7.01, P = 0.021). Perineural invasion on systematic biopsyalso appeared to improve the performance of our multivariable model (HR 5.33, P = 0.052), though it was not statistically significant when using a cutoff of <0.05. Accuracy for predicting successful HA was 0.32 and improved to 0.74 if PNI or cribriform were excluded and 0.84 if both were excluded. CONCLUSIONS: In a retrospective analysis of RP patients who underwent preoperative MRI/US fusion biopsy, current selection criteria for prostatic HA based on NCCN intermediate-risk stratification failed to accurately identify appropriate candidates in 68.5% of patients. Cribriform pattern and PNI detected on biopsy reduced the failure of hemigland selection criteria to 43%. These criteria should be routinely reported on biopsy pathology and taken into consideration when selecting patients for HA in prospective clinical trials.

Incorporation and validation of clinically relevant performance metrics of simulation (CRPMS) into a novel full-immersion simulation platform for nerve-sparing robot-assisted radical prostatectomy (NS-RARP) utilizing three-dimensional printing and hydrogel casting technology.

OBJECTIVES: To incorporate and validate clinically relevant performance metrics of simulation (CRPMS) into a hydrogel model for nerve-sparing robot-assisted radical prostatectomy (NS-RARP). MATERIALS AND METHODS: Anatomically accurate models of the human pelvis, bladder, prostate, urethra, neurovascular bundle (NVB) and relevant adjacent structures were created from patient MRI by injecting polyvinyl alcohol (PVA) hydrogels into three-dimensionally printed injection molds. The following steps of NS-RARP were simulated: bladder neck dissection; seminal vesicle mobilization; NVB dissection; and urethrovesical anastomosis (UVA). Five experts (caseload >500) and nine novices (caseload <50) completed the simulation. Force applied to the NVB during the dissection was quantified by a novel tension wire sensor system fabricated into the NVB. Post-simulation margin status (assessed by induction of chemiluminescent reaction with fluorescent dye mixed into the prostate PVA) and UVA weathertightness (via a standard 180-mL leak test) were also assessed. Objective scoring, using Global Evaluative Assessment of Robotic Skills (GEARS) and Robotic Anastomosis Competency Evaluation (RACE), was performed by two blinded surgeons. GEARS scores were correlated with forces applied to the NVB, and RACE scores were correlated with UVA leak rates. RESULTS: The expert group achieved faster task-specific times for nerve-sparing (P = 0.007) and superior surgical margin results (P = 0.011). Nerve forces applied were significantly lower for the expert group with regard to maximum force (P = 0.011), average force (P = 0.011), peak frequency (P = 0.027) and total energy (P = 0.003). Higher force sensitivity (subcategory of GEARS score) and total GEARS score correlated with lower nerve forces (total energy in Joules) applied to NVB during the simulation with a correlation coefficient (r value) of -0.66 (P = 0.019) and -0.87 (P = 0.000), respectively. Both total and force sensitivity GEARS scores were significantly higher in the expert group compared to the novice group (P = 0.003). UVA leak rate highly correlated with total RACE score r value = -0.86 (P = 0.000). Mean RACE scores were also significantly different between novices and experts (P = 0.003). CONCLUSION: We present a realistic, feedback-driven, full-immersion simulation platform for the development and evaluation of surgical skills pertinent to NS-RARP. The correlation of validated objective metrics (GEARS and RACE) with our CRPMS suggests their application as a novel method for real-time assessment and feedback during robotic surgery training. Further work is required to assess the ability to predict live surgical outcomes.

Multi-institutional Clinical Tool for Predicting High-risk Lesions on 3Tesla Multiparametric Prostate Magnetic Resonance Imaging.

BACKGROUND: Multiparametric magnetic resonance imaging (mpMRI) for prostate cancer detection without careful patient selection may lead to excessive resource utilization and costs. OBJECTIVE: To develop and validate a clinical tool for predicting the presence of high-risk lesions on mpMRI. DESIGN, SETTING, AND PARTICIPANTS: Four tertiary care centers were included in this retrospective and prospective study (BiRCH Study Collaborative). Statistical models were generated using 1269 biopsy-naive, prior negative biopsy, and active surveillance patients who underwent mpMRI. Using age, prostate-specific antigen, and prostate volume, a support vector machine model was developed for predicting the probability of harboring Prostate Imaging Reporting and Data System 4 or 5 lesions. The accuracy of future predictions was then prospectively assessed in 214 consecutive patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Receiver operating characteristic, calibration, and decision curves were generated to assess model performance. RESULTS AND LIMITATIONS: For biopsy-naïve and prior negative biopsy patients (n=811), the area under the curve (AUC) was 0.730 on internal validation. Excellent calibration and high net clinical benefit were observed. On prospective external validation at two separate institutions (n=88 and n=126), the machine learning model discriminated with AUCs of 0.740 and 0.744, respectively. The final model was developed on the Microsoft Azure Machine Learning platform (birch.azurewebsites.net). This model requires a prostate volume measurement as input. CONCLUSIONS: In patients who are naïve to biopsy or those with a prior negative biopsy, BiRCH models can be used to select patients for mpMRI. PATIENT SUMMARY: In this multicenter study, we developed and prospectively validated a calculator that can be used to predict prostate magnetic resonance imaging (MRI) results using patient age, prostate-specific antigen, and prostate volume as input. This tool can aid health care professionals and patients to make an informed decision regarding whether to get an MRI.

Historical and contemporary perspectives on cribriform morphology in prostate cancer.

The Gleason scoring system is widely used for the grading and prognostication of prostate cancer. A Gleason pattern 4 subtype known as cribriform morphology has now been recognized as an aggressive and often lethal pattern of prostate cancer. The vast majority of published and ongoing prostate cancer studies still do not acknowledge the prognostic differences between various Gleason pattern 4 morphologies. As a result, current treatment recommendations are likely to be imprecise and not tailored towards patients who are most likely to die from the disease. Use of active surveillance for patients with Gleason score 3 + 4 prostate cancer has been suggested. However, the success of such paradigms would require cribriform morphology to be reported at the time of prostate biopsy, as patients harbouring such a pattern are poor candidates for surveillance. To date, only a limited number of studies have described the molecular alterations that occur in the cribriform morphological pattern. Further refinement of prostate cancer grading paradigms to distinguish cribriform from noncribriform Gleason pattern 4 is essential.

A Comprehensive Analysis of Cribriform Morphology on Magnetic Resonance Imaging/Ultrasound Fusion Biopsy Correlated with Radical Prostatectomy Specimens.

PURPOSE: Recently a large body of evidence has emerged indicating that cribriform morphology is an aggressive prostate cancer morphological pattern associated with higher cancer specific mortality. In a comprehensive analysis we compared traditional and contemporary prostate biopsy techniques to detect prostate cancer with cribriform morphology with radical prostatectomy serving as the reference standard. MATERIALS AND METHODS: We queried a retrospectively maintained, single institution, multiparametric magnetic resonance imaging database of 1,001 patients to identify 240 who underwent magnetic resonance imaging-ultrasound fusion targeted biopsy and concurrent systematic biopsy from December 2014 to December 2016. Of the 3,978 biopsy cores obtained 694 positive cores were rereviewed by a genitourinary pathologist for pattern 4 subtype (cribriform, fused and poorly formed glands). Using paired analysis pathological results among 3 biopsy methods (systematic biopsy, targeted biopsy and systematic plus targeted biopsy) were compared. Prostatectomy specimens were also pathologically reviewed. RESULTS: Systematic plus targeted biopsy was superior to systematic biopsy alone or targeted biopsy alone to detect cribriform morphology (all p <0.0001). On final histopathology cribriform tumor foci were associated with an increased percent of pattern 4 involvement and extraprostatic extension (p <0.0001 and 0.003, respectively). Only 17.4% of cribriform tumors in pure form were visible on multiparametric magnetic resonance imaging. Based on final histopathology the sensitivity of systematic biopsy, targeted biopsy and systematic plus targeted biopsy for cribriform morphology was 20.7%, 28.6% and 37.1%, respectively. CONCLUSIONS: Although systematic plus targeted biopsy was the most accurate biopsy method to detect cribriform morphology, biopsy sensitivity and specificity remained poor.

Multi-institutional nomogram predicting benign prostate pathology on magnetic resonance/ultrasound fusion biopsy in men with a prior negative 12-core systematic biopsy.

BACKGROUND: Prostate multiparametric magnetic resonance imaging (mpMRI) may be recommended for patients with a prior negative systematic biopsy (SB). However, a proportion of these patients will continue to have no prostate cancer (PCa) identified on magnetic resonance/ultrasound fusion biopsy (FB) despite abnormal mpMRI findings. METHODS: In this multi-institutional, retrospective study, clinical and mpMRI parameters were assessed for 285 consecutive patients with at least 1 prior negative biopsy who underwent FB for a Prostate Imaging Reporting and Data System (PI-RADS) score of 3 to 5 at the University of Rochester Medical Center from December 2014 to December 2016, or at the University of Alabama at Birmingham from February 2014 to February 2017. Nomograms were generated for predicting benign prostate pathology on both the targeted biopsy and the concurrent SB. RESULTS: Benign pathology was found in 132 of 285 patients (46.3%). In a multivariate analysis, the predictors of benign prostate pathology on FB were age, prostate-specific antigen, prostate volume, and PI-RADS score. The predicted probabilities were plotted on a receiver operating characteristic curve, and the area under the curve was 0.825. The nomogram demonstrated excellent calibration and a high net benefit in a decision curve analysis. With a theoretical cutoff probability of ≥0.7 used to recommend deferment of FB, 61 of 285 patients (21.4%) would have avoided an unnecessary biopsy, and only 4 of 285 patients (1.4%) with PCa with a Gleason score ≥ 3 + 4 would have been missed. CONCLUSIONS: False-positive mpMRI examinations may occur in up to 46.3% of patients with a prior negative biopsy. Thus, a multi-institutional nomogram has been developed and validated for predicting benign pathology after FB in patients with a prior negative biopsy, and this may help to reduce the number of unnecessary biopsies in the setting of abnormal mpMRI findings. Cancer 2018;124:278-85. © 2017 American Cancer Society.

Institutional Learning Curve Associated with Implementation of a Magnetic Resonance/Transrectal Ultrasound Fusion Biopsy Program Using PI-RADS™ Version 2: Factors that Influence Success.

INTRODUCTION: We assessed the institutional learning curve associated with adopting fusion biopsy using PI-RADS™ (Prostate Imaging-Reporting and Data System) Version 2 (v2) to detect clinically significant prostate cancer, defined as Gleason 7 or greater in men with prior negative biopsies, and identified patient and technical factors that predict success in detecting clinically significant prostate cancer. METHODS: A total of 113 consecutive patients with at least 1 prior negative biopsy and multiparametric magnetic resonance imaging examination of the prostate with a PI-RADS 3 or greater index lesion underwent fusion biopsy at a single academic center previously naïve to fusion biopsy technology. Outcomes include detection rates for Gleason 6 cancer, clinically significant prostate cancer and any cancer. Multiple logistic regression with model selection was used to select covariates having significant effects on the outcome. RESULTS: Prostate cancer was identified in 52% of patients with prior negative prostate biopsies. Among the patients diagnosed with prostate cancer 80% had clinically significant cancer. The clinically significant prostate cancer detection rates using fusion biopsy when a PI-RADS 3, 4 or 5 index lesion was present on multiparametric magnetic resonance imaging were 6%, 46% and 66%, respectively. PI-RADS v2 score had a predictive accuracy (AUC) of 0.79 for clinically significant prostate cancer detection. Institutional experience over time, magnetic resonance imaging estimated prostate volume and PI-RADS v2 score were independent predictors of clinically significant prostate cancer using fusion biopsy. CONCLUSIONS: Since fusion biopsy is a highly technique driven process, development of internal quality measures to assess the institutional learning curve and the quality of PI-RADS v2 scoring is critical with the adoption of this technology.

Magnetic resonance imaging detection of prostate cancer in men with previous negative prostate biopsy.

Use of transrectal ultrasound guided systematic prostate biopsy has poor diagnostic accuracy for prostate cancer (PCa) detection. Recently multiparametric MRI (mpMRI) of the prostate and MR/US fusion biopsy has been gaining popularity for men who have previously undergone a negative biopsy. We performed PubMed® and Web of Science® searches to identify studies on this subject, particularly focusing on studies consisting of patients who have had at least one previously negative biopsy. Across the literature, when a suspicious lesion is found on mpMRI, MR/US fusion biopsy has consistently demonstrated higher detection rate for any PCa and clinically significant PCa (csPCa) compared to the traditional repeat systematic biopsy (SB) approach. Furthermore, anteriorly located tumors are frequently identified using MR targeted biopsy (TB), suggesting that an MR guided approach allows for increased accuracy for detecting tumors commonly missed by systematic biopsies. We conclude that men with a prior negative biopsy and continued suspicion of PCa should strongly be encouraged to get a prostate mpMRI prior to a repeat biopsy.

Impact of Gleason Subtype on Prostate Cancer Detection Using Multiparametric Magnetic Resonance Imaging: Correlation with Final Histopathology.

PURPOSE: We determined whether Gleason pattern 4 architecture impacts tumor visibility on multiparametric magnetic resonance imaging and correlates with final histopathology. MATERIALS AND METHODS: A total of 83 tumor foci were identified in 22 radical prostatectomy specimens from patients with a prior negative biopsy who underwent magnetic resonance/ultrasound fusion biopsy followed by radical prostatectomy from January 2015 to July 2016. A genitourinary pathologist rereviewed tumor foci for Gleason architectural subtype. Each prostate imaging reporting and data system category 3 to 5 lesion on multiparametric magnetic resonance imaging was paired with its corresponding pathological tumor focus. Univariable and multivariable analyses were performed to determine predictors of tumor visibility. RESULTS: Of the 83 tumor foci identified 26 (31%) were visible on multiparametric magnetic resonance imaging, 33 (40%) were Gleason score 3+3 and 50 (60%) were Gleason score 3+4 or greater. Among tumor foci containing Gleason pattern 4, increasing tumor size and noncribriform predominant architecture were the only independent predictors of tumor detection on multivariable analysis (p = 0.002 and p = 0.011, respectively). For tumor foci containing Gleason pattern 4, 0.5 cm or greater, multiparametric magnetic resonance imaging detected 10 of 13 (77%), 5 of 14 (36%) and 9 of 10 (90%) for poorly formed, cribriform and fused architecture, respectively (p = 0.01). The size threshold for the detection of cribriform tumors was higher than that of other architectural patterns. Furthermore, cribriform pattern was identified more frequently on systematic biopsy than on targeted biopsy. CONCLUSIONS: Reduced visibility of cribriform pattern on multiparametric magnetic resonance imaging has significant ramifications for prostate cancer detection, surveillance and focal therapy.

Magnetic Resonance Imaging-Transrectal Ultrasound Guided Fusion Biopsy to Detect Progression in Patients with Existing Lesions on Active Surveillance for Low and Intermediate Risk Prostate Cancer.

PURPOSE: Active surveillance is an established option for men with low risk prostate cancer. Multiparametric magnetic resonance imaging with magnetic resonance imaging-transrectal ultrasound fusion guided biopsy may better identify patients for active surveillance compared to systematic 12-core biopsy due to improved risk stratification. To our knowledge the performance of multiparametric magnetic resonance imaging in following men on active surveillance with visible lesions is unknown. We evaluated multiparametric magnetic resonance imaging and magnetic resonance imaging-transrectal ultrasound fusion guided biopsy to monitor men on active surveillance. MATERIALS AND METHODS: This retrospective review included men from 2007 to 2015 with prostate cancer on active surveillance in whom magnetic resonance imaging visible lesions were monitored by multiparametric magnetic resonance imaging and fusion guided biopsy. Progression was defined by ISUP (International Society of Urological Pathology) grade group 1 to 2 and ISUP grade group 2 to 3. Significance was considered at p ≤0.05. RESULTS: A total of 166 patients on active surveillance with 2 or more fusion guided biopsies were included in analysis. Mean followup was 25.5 months. Of the patients 29.5% had pathological progression. Targeted biopsy alone identified 44.9% of patients who progressed compared to 30.6% identified by systematic 12-core biopsy alone (p = 0.03). Fusion guided biopsy detected 26% more cases of pathological progression on surveillance biopsy compared to systematic 12-core biopsy. Progression on multiparametric magnetic resonance imaging was the sole predictor of pathological progression at surveillance biopsy (p = 0.013). Multiparametric magnetic resonance imaging progression in the entire cohort had 81% negative predictive value, 35% positive predictive value, 77.6% sensitivity and 40.5% specificity in detecting pathological progression. CONCLUSIONS: Multiparametric magnetic resonance imaging progression predicts the risk of pathological progression. Patients with stable multiparametric magnetic resonance imaging findings have a low rate of progression. Incorporating fusion guided biopsy in active surveillance nearly doubled our detection of pathological progression compared to systematic 12-core biopsy.

Tumor contact with prostate capsule on magnetic resonance imaging: A potential biomarker for staging and prognosis.

BACKGROUND: The high-spatial resolution of multiparametric magnetic resonance imaging (mpMRI) has improved the detection of clinically significant prostate cancer. mpMRI characteristics (extraprostatic extension [EPE], number of lesions, etc.) may predict final pathological findings (positive lymph node [pLN] and pathological ECE [pECE]) and biochemical recurrence (BCR). Tumor contact length (TCL) on MRI, defined as the length of a lesion in contact with the prostatic capsule, is a novel marker with promising early results. We aimed to evaluate TCL as a predictor of +pathological EPE (+pEPE),+pathological LN (+pLN), and BCR in patients undergoing robotic-assisted laparoscopic radical prostatectomy. MATERIALS AND METHODS: A review was performed of a prospectively maintained single-institution database of men with prostate cancer who underwent prostate mpMRI followed by robotic-assisted laparoscopic radical prostatectomy without prior therapy from 2007 to 2015. TCL was measured using T2-weighted magnetic resonance images. Logistic and Cox regression analysis were used to assess associations of clinical, imaging, and histopathological variables with pEPE, pLN, and BCR. Receiver operating characteristic curves were used to characterize and compare TCL performance with Partin tables. RESULTS: There were 87/379 (23.0%)+pEPE, 18/384 (4.7%)+pLN, and 33/371 (8.9%) BCR patients. Patients with adverse pathology/oncologic outcomes had longer TCL compared to those without adverse outcomes (+pEPE: 19.8 vs. 10.1mm, P<0.0001,+pLN: 38.0 vs. 11.7mm, P<0.0001, and BCR: 19.2 vs. 11.2mm, P = 0.001). On multivariate analysis, TCL remained a predictor of+pEPE (odds ratio: 1.04, P = 0.001),+pLN (odds ratio: 1.07, P<0.0001), and BCR (hazard ratio: 1.03, P = 0.02). TCL thresholds for predicting+pEPE and+pLN were 12.5 and 19.7mm, respectively. TCL alone was found to have good predictive ability for+pEPE and+PLN (pEPE:TCLAUC: 0.71 vs. PartinAUC: 0.66, P = 0.21; pLN:TCLAUC: 0.77 vs. PartinAUC: 0.88, P = 0.04). CONCLUSION: We demonstrate that TCL is an independent predictor of+pEPE, +pLN, and BCR. If validated, this imaging biomarker may facilitate and inform patient counseling and decision-making.