Characterization of Demographical Histologic Diversity in Small Renal Masses With the Clear Cell Likelihood Score.

OBJECTIVE: This study aimed to develop a diagnostic model to estimate the distribution of small renal mass (SRM; ≤4 cm) histologic subtypes for patients with different demographic backgrounds and clear cell likelihood score (ccLS) designations. MATERIALS AND METHODS: A bi-institution retrospective cohort study was conducted where 347 patients (366 SRMs) underwent magnetic resonance imaging and received a ccLS before pathologic confirmation between June 2016 and November 2021. Age, sex, race, ethnicity, socioeconomic status, body mass index (BMI), and the ccLS were tabulated. The socioeconomic status for each patient was determined using the Area Deprivation Index associated with their residential address. The magnetic resonance imaging-derived ccLS assists in the characterization of SRMs by providing a likelihood of clear cell renal cell carcinoma (ccRCC). Pathological subtypes were grouped into four categories (ccRCC, papillary renal cell carcinoma, other renal cell carcinomas, or benign). Generalized estimating equations were used to estimate probabilities of the pathological subtypes across different patient subgroups. RESULTS: Race and ethnicity, BMI, and ccLS were significant predictors of histology (all P < 0.001). Obese (BMI, ≥30 kg/m 2 ) Hispanic patients with ccLS of ≥4 had the highest estimated rate of ccRCC (97.1%), and normal-weight (BMI, <25 kg/m 2 ) non-Hispanic Black patients with ccLS ≤2 had the lowest (0.2%). The highest estimated rates of papillary renal cell carcinoma were found in overweight (BMI, 25-30 kg/m 2 ) non-Hispanic Black patients with ccLS ≤2 (92.3%), and the lowest, in obese Hispanic patients with ccLS ≥4 (<0.1%). CONCLUSIONS: Patient race, ethnicity, BMI, and ccLS offer synergistic information to estimate the probabilities of SRM histologic subtypes.

The Operating Room Black Box: Understanding Adherence to Surgical Checklists.

OBJECTIVE: We report for the first time the use of the Operating Room Black Box (ORBB) to track checklist compliance, engagement, and quality. BACKGROUND: Implementation of operative checklists is associated with improved outcomes. Compliance is difficult to monitor. Most studies report either no assessment of checklist compliance or deployed in-person short-term assessment. The ORBB a novel artificially intelligence-driven data analytic platform affords the opportunity to assess checklist compliance without disrupting surgical workflow. METHODS: This was a retrospective review of prospectively collected ORBB data. Operative cases included elective surgery at a quaternary referral center. Cases were analyzed as prepolicy change (first 9 months) or as a postpolicy change (last 9 months). Measures of checklist compliance, engagement, and quality were assessed. RESULTS: There were 3879 cases that were performed and monitored for checklist compliance between August 15, 2020, and February 20, 2022. The overall scores for compliance, engagement, and quality were 81%, 84%, and 67% respectively. When broken down by phase, the scores for time-out were compliance 100%, engagement 98%, and quality 61%. Scores for the debrief phase were 81% for compliance, 98% for engagement, and 66% for quality. After a hospital policy change, the debrief scores improved significantly (85%; P <0.001 for compliance, 88%; P <0.001 for engagement and 71%; P <0.001 for quality). CONCLUSIONS: ORBB provides the unprecedented ability to assess not only compliance with surgical safety checklists but also engagement and quality. Utilization of this technology allows the assessment of compliance in near real time and to accurately address safety threats that may arise from noncompliance.

How We Do It: Managing the Indeterminate Renal Mass with the MRI Clear Cell Likelihood Score.

The widespread use of cross-sectional imaging has led to a continuous increase in the number of incidentally detected indeterminate renal masses. Frequently, these clinical scenarios involve an older patient with comorbidities and a small renal mass (≤4 cm). Despite aggressive treatment in early stages of the disease, a clear positive effect in reducing kidney cancer-specific mortality is lacking, indicating that many renal cancers exhibit an indolent oncologic behavior. Furthermore, in general, one in five small renal masses is histologically benign and may not benefit from aggressive treatment. Although active surveillance is increasingly recognized as a management option for some patients, the absence of reliable clinical and imaging predictive biologic markers of aggressiveness can contribute to patient anxiety and limit its use in clinical practice. A standardized approach to the image interpretation of solid renal masses has not been broadly implemented. The clear cell likelihood score (ccLS) derived from multiparametric MRI is useful in noninvasively identifying the clear cell subtype, the most common and aggressive form of kidney cancer. Herein, a review of the ccLS is presented, including a step-by-step guide for image interpretation and additional guidance for its implementation in clinical practice.

Association of Clear Cell Likelihood Score on MRI and Growth Kinetics of Small Solid Renal Masses on Active Surveillance.

BACKGROUND. The lack of validated imaging markers to characterize biologic aggressiveness of small renal masses (SRMs)-defined as those categorized as cT1a and 4 cm and smaller-hinders medical decision-making among available initial management strategies. OBJECTIVE. The purpose of this article was to explore the association of the clear cell likelihood score (ccLS) on MRI with growth rates and progression of SRMs. METHODS. This retrospective study included consecutive SRMs assigned a ccLS on clinical MRI examinations performed between June 2016 and November 2019 at an academic tertiary-care medical center or its affiliated safety net hospital system. The ccLS reports the likelihood that the SRM represents clear cell renal cell carcinoma (ccRCC) from 1 (very unlikely) to 5 (very likely). The ccLS was extracted from clinical reports. Tumor size measurements were extracted from available prior and follow-up cross-sectional imaging examinations, through June 2020. Serial tumor size measurements were fit to linear and exponential growth curves. Estimated growth rates were grouped by the assigned ccLS. Tumor progression was defined by development of large size (> 4 cm in at least two consecutive measurements) and/or rapid growth (doubling of volume within 1 year). Differences among ccLS groups were evaluated using Kruskal-Wallis tests. Correlations between ccLS and growth rate were evaluated by Spearman correlation (ρ). RESULTS. Growth rates of 386 SRMs (100 ccLS 1-2, 75 ccLS 3, and 211 ccLS 4-5) from 339 patients (median age, 65 years; 198 men, 141 women) were analyzed. Median follow-up was 1.2 years. The ccLS was correlated with growth rates by size (ρ = 0.19; p < .001; ccLS 4-5, 9%/year; ccLS 1-2, 5%/year; p < .001) and by volume (ρ = 0.14; p = .006; ccLS 4-5, 29%/year; ccLS 1-2, 16%/year; p < .001). Disease progression (observed in 49 SRMs) was not significantly associated with ccLS group (p = .61). Two patients (0.6%) developed metastases during active surveillance: one ccLS 1 was a type 2 papillary renal cell carcinoma and one ccLS 4 was ccRCC. CONCLUSION. Growth is associated with ccLS in SRMs, with higher ccLS correlating with faster growth. CLINICAL IMPACT. SRMs with lower ccLS may be considered for active surveillance, whereas SRMs with higher ccLS may warrant earlier intervention. The noninvasive ccLS derived from MRI correlates with growth rate of SRMs and may help guide personalized management.

Prospective performance of clear cell likelihood scores (ccLS) in renal masses evaluated with multiparametric magnetic resonance imaging.

OBJECTIVES: Solid renal masses have unknown malignant potential with commonly utilized imaging. Biopsy can offer a diagnosis of cancer but has a high non-diagnostic rate and complications. Reported use of multiparametric magnetic resonance imaging (mpMRI) to diagnose aggressive histology (i.e., clear cell renal cell carcinoma (ccRCC)) via a clear cell likelihood score (ccLS) was based on retrospective review of cT1a tumors. We aim to retrospectively assess the diagnostic performance of ccLS prospectively assigned to renal masses of all stages evaluated with mpMRI prior to histopathologic evaluation. METHODS: In this retrospective cohort study from June 2016 to November 2019, 434 patients with 454 renal masses from 2 institutions with heterogenous patient populations underwent mpMRI with prospective ccLS assignment and had pathologic diagnosis. ccLS performance was assessed by contingency table analysis. The association between ccLS and ccRCC was assessed with logistic regression. RESULTS: Mean age and tumor size were 60 ± 13 years and 5.4 ± 3.8 cm. Characteristics were similar between institutions except for patient age and race (both p < 0.001) and lesion laterality and histology (both p = 0.04). The PPV of ccLS increased with each increment in ccLS (ccLS1 5% [3/55], ccLS2 6% [3/47], ccLS3 35% [20/57], ccLS4 78% [85/109], ccLS5 93% [173/186]). Pooled analysis for ccRCC diagnosis revealed sensitivity 91% (258/284), PPV 87% (258/295) for ccLS ≥ 4, and specificity 56% (96/170), NPV 94% (96/102) for ccLS ≤ 2. Diagnostic performance was similar between institutions. CONCLUSIONS: We confirm the optimal diagnostic performance of mpMRI to identify ccRCC in all clinical stages. High PPV and NPV of ccLS can help inform clinical management decision-making. KEY POINTS: • The positive predictive value of the clear cell likelihood score (ccLS) for detecting clear cell renal cell carcinoma was 5% (ccLS1), 6% (ccLS2), 35% (ccLS3), 78% (ccLS4), and 93% (ccLS5). Sensitivity of ccLS ≥ 4 and specificity of ccLS ≤ 2 were 91% and 56%, respectively. • When controlling for confounding variables, ccLS is an independent risk factor for identifying clear cell renal cell carcinoma. • Utilization of the ccLS can help guide clinical care, including the decision for renal mass biopsy, reducing the morbidity and risk to patients.

Single Port Robotic Surgery in Urology.

PURPOSE: To provide a comprehensive review on the new da Vinci SP (single port) robotic surgical system. The published literature to date within urology and a description of the new system will be discussed. FINDINGS: There are currently no high-quality published studies with the SP robotic system. All studies are case series, many with 10 or fewer patients. However, all studies have found the SP system to be safe and feasible in performing most urological procedures. Renal and pelvic surgery using the SP robotic system is safe and feasible in the hands of expert robotic surgeons. Long-term, high-quality data is lacking. While the current high price and the learning curve will limit the SP systems' use in many health care systems, new updates and the release of robotic surgical systems from other developers may help drive down costs and encourage uptake.

Clinical and radiographic outcomes following salvage intervention for ureteropelvic junction obstruction.

PURPOSE: We aimed to assess failure rates of salvage interventions and changes in split kidney function (SKF) following failed primary repair of ureteropelvic junction obstruction (UPJO). MATERIALS AND METHODS: A retrospective review of adult patients at an academic medical center who underwent salvage intervention following primary treatment for UPJO was performed. Symptomatic failure was defined as significant flank pain. Radiographic failure was defined as no improvement in drainage or a decrease in SKF by ≥7%. Overall failure, the primary outcome, was defined as symptomatic failure, radiographic failure, or both. RESULTS: Between 2008-2017, 34 patients (median age 38 years, 50% men) met study criteria. UPJO management was primary pyeloplasty/secondary endopyelotomy for 21/34 (62%), primary pyeloplasty/secondary pyeloplasty for 6/34 (18%), and primary endopyelotomy/secondary pyeloplasty for 7/34 (21%). Median follow-up was 3.3 years following secondary intervention. Patients undergoing primary pyeloplasty/secondary endopyelotomy had significantly higher overall failure than those undergoing primary pyeloplasty/secondary pyeloplasty (16/21 [76%] vs. 1/6 [17%], p=0.015). Among patients undergoing secondary endopyelotomy, presence of a stricture on retrograde pyelogram, stricture length, and SKF were not associated with symptomatic, radiographic, or overall failure. Serial renography was performed for 28/34 (82%) patients and 2/28 (7%) had a significant decline in SKF. CONCLUSIONS: Following failed primary pyeloplasty, secondary endopyelotomy had a greater overall failure rate than secondary pyeloplasty. No radiographic features assessed were associated with secondary endopyelotomy failure. Secondary intervention overall failure rates were higher than reported in the literature. Unique to this study, serial renography demonstrated that significant functional loss was overall infrequent.

Ten-Year Outcomes of Renal Tumor Radio Frequency Ablation.

PURPOSE: We reviewed long-term oncologic outcomes in patients with renal tumors treated with radio frequency ablation more than 10 years ago. MATERIALS AND METHODS: We retrospectively reviewed the records of patients with renal tumors who underwent radio frequency ablation from November 2000 to August 2007. Demographic, clinical and radiological data were assessed to determine evidence of disease recurrence. Patients with familial renal cell carcinoma syndromes were excluded from study. We calculated disease-free, metastasis-free, cancer specific and overall survival with the Kaplan-Meier method. Subgroup analysis of patients who had at least 10 years followup was performed to determine actual 10-year survival. Analysis was also performed based on tumor size. RESULTS: A total of 112 tumors in 106 patients were treated with radio frequency ablation. Median followup was 79 months (IQR 28.9-121.1) and mean ± SD tumor size was 2.5 ± 0.8 cm. Initial technical success was achieved in 97% of cases. There were 10 recurrences. Kaplan-Meier 6-year disease-free and cancer specific survival rates were 89% and 96%, respectively. Disease-free survival decreased to 68% for tumors greater than 3 cm. In the subgroup with at least 10-year followup the actual disease-free, cancer specific and overall survival rates were 82%, 94% and 49%, respectively. No patient experienced recurrence after 5 years. CONCLUSIONS: Radio frequency ablation is a safe and effective treatment option for small renal masses less than 3 cm in diameter. We report good oncologic outcomes with actual 10-year survival data. No recurrence developed after 5 years. Tumors greater than 3 cm have significantly poorer outcomes.

Role of Virtual Biopsy in the Management of Renal Masses.

OBJECTIVE. Renal masses comprise a heterogeneous group of pathologic conditions, including benign and indolent diseases and aggressive malignancies, complicating management. In this article, we explore the emerging role of imaging to provide a comprehensive noninvasive characterization of a renal mass-so-called "virtual biopsy"-and its potential use in the management of patients with renal tumors. CONCLUSION. Percutaneous renal mass biopsy (RMB) remains a valuable method to provide a presurgical histopathologic diagnosis of renal masses, but it is an invasive procedure and is not always feasible. Accumulating data support the use of imaging features to predict histopathology of renal masses. Imaging may help address some of the inherent limitations of RMB, and in certain settings, a multimodal clinical approach may allow decreasing the need for RMB.

Diagnostic Performance and Interreader Agreement of a Standardized MR Imaging Approach in the Prediction of Small Renal Mass Histology.

Purpose To assess the diagnostic performance and interreader agreement of a standardized diagnostic algorithm in determining the histologic type of small (≤4 cm) renal masses (SRMs) with multiparametric magnetic resonance (MR) imaging. Materials and Methods This single-center retrospective HIPAA-compliant institutional review board-approved study included 103 patients with 109 SRMs resected between December 2011 and July 2015. The requirement for informed consent was waived. Presurgical renal MR images were reviewed by seven radiologists with diverse experience. Eleven MR imaging features were assessed, and a standardized diagnostic algorithm was used to determine the most likely histologic diagnosis, which was compared with histopathology results after surgery. Interreader variability was tested with the Cohen κ statistic. Regression models using MR imaging features were used to predict the histopathologic diagnosis with 5% significance level. Results Clear cell renal cell carcinoma (RCC) and papillary RCC were diagnosed, with sensitivities of 85% (47 of 55) and 80% (20 of 25), respectively, and specificities of 76% (41 of 54) and 94% (79 of 84), respectively. Interreader agreement was moderate to substantial (clear cell RCC, κ = 0.58; papillary RCC, κ = 0.73). Signal intensity (SI) of the lesion on T2-weighted MR images and degree of contrast enhancement (CE) during the corticomedullary phase were independent predictors of clear cell RCC (SI odds ratio [OR]: 3.19; 95% confidence interval [CI]: 1.4, 7.1; P = .003; CE OR, 4.45; 95% CI: 1.8, 10.8; P < .001) and papillary RCC (CE OR, 0.053; 95% CI: 0.02, 0.2; P < .001), and both had substantial interreader agreement (SI, κ = 0.69; CE, κ = 0.71). Poorer performance was observed for chromophobe histology, oncocytomas, and minimal fat angiomyolipomas, (sensitivity range, 14%-67%; specificity range, 97%-99%), with fair to moderate interreader agreement (κ range = 0.23-0.43). Segmental enhancement inversion was an independent predictor of oncocytomas (OR, 16.21; 95% CI: 1.0, 275.4; P = .049), with moderate interreader agreement (κ = 0.49). Conclusion The proposed standardized MR imaging-based diagnostic algorithm had diagnostic accuracy of 81% (88 of 109) and 91% (99 of 109) in the diagnosis of clear cell RCC and papillary RCC, respectively, while achieving moderate to substantial interreader agreement among seven radiologists. © RSNA, 2018 Online supplemental material is available for this article.