Current patterns of presentation and treatment of renal masses: a clinical research office of the endourological society prospective study

Is there enough evidence supporting the clinical adoption of clear cell likelihood score (ccLS)? An updated systematic review and meta-analysis

OBJECTIVE

To review the evidence for clinical adoption of clear cell likelihood score (ccLS) for identifying clear cell renal cell carcinoma (ccRCC) from small renal masses (SRMs).

METHODS

We distinguished the literature on ccLS for identifying ccRCC via systematic search using PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and Wanfang Data until 31 March, 2024. The risk of bias and concern on application was assessed using the modified quality assessment of diagnostic accuracy studies (QUADAS-2) tool. The level of evidence supporting the clinical adoption of ccLS for identifying ccRCC was determined based on meta-analyses.

RESULTS

Eight MRI studies and three CT studies were included. The risk of bias and application were mainly related to the index test and flow and timing, due to incomplete imaging protocol, unclear rating process, and inappropriate interval between imaging and surgery. The diagnostic odds ratios (95% confidence intervals) of MRI and CT ccLS were 14.69 (9.71-22.22; 6 studies, 1429 SRM, 869 ccRCC), and 5.64 (3.34-9.54; 3 studies, 296 SRM, 147 ccRCC), respectively, for identifying ccRCC from SRM. The evidence level for clinical adoption of MRI and CT ccLS were both rated as weak. MRI ccLS version 2.0 potentially has better diagnostic performance than version 1.0 (1 study, 700 SRM, 509 ccRCC). Both T2-weighted-imaging with or without fat suppression might be suitable for MRI ccLS version 2.0 (1 study, 111 SRM, 82 ccRCC).

CONCLUSION

ccLS shows promising diagnostic performance for identifying ccRCC from SRM, but the evidence for its adoption in clinical routine remains weak.

CRITICAL RELEVANCE STATEMENT

Although clear cell likelihood score (ccLS) demonstrates promising performance for detecting clear cell renal cell carcinoma, additional evidence is crucial to support its routine use as a tool for both initial diagnosis and active surveillance of small renal masses.

KEY POINTS

Clear cell likelihood score is designed for the evaluation of small renal masses. Both CT and MRI clear cell likelihood scores are accurate and efficient. More evidence is necessary for the clinical adoption of a clear cell likelihood score.

Bosniak Classification of Cystic Renal Masses: Looking Back, Looking Forward

RATIONALE AND OBJECTIVES

According to the 2019 update of the Bosniak classification, the main imaging features that need to be evaluated to achieve a correct characterization of renal cystic masses include the thickness of walls and septa, the number of septa, the appearance of walls and septa, the attenuation/intensity on non-contrast CT/MRI and the presence of unequivocally perceived or measurable enhancement of walls and septa. Despite the improvement deriving from a quantitative evaluation of imaging features, certain limitations seem to persist and some possible scenarios that can be encountered in clinical practice are still missing.

MATERIALS AND METHODS

A deep analysis of the 2019 update of the Bosniak classification was performed.

RESULTS

The most notable potential flaws concern: (1) the quantitative measurement of the walls and septa; (2) the fact that walls and septa > 2 mm are always referred to as "enhancing", not considering the alternative scenario; (3) the description of some class II masses partially overlaps with each other and with the definition of class I masses and (4) the morphological variations of cystic masses over time is not considered.

CONCLUSION

The present paper analyzes in detail the limitations of the 2019 Bosniak classification to improve this important tool and facilitate its use in daily radiological practice.

Update on Renal Cell Carcinoma Diagnosis with Novel Imaging Approaches

This review highlights recent advances in renal cell carcinoma (RCC) imaging. It begins with dual-energy computed tomography (DECT), which has demonstrated a high diagnostic accuracy in the evaluation of renal masses. Several studies have suggested the potential benefits of iodine quantification, particularly for distinguishing low-attenuation, true enhancing solid masses from hyperdense cysts. By determining whether or not a renal mass is present, DECT could avoid the need for additional imaging studies, thereby reducing healthcare costs. DECT can also provide virtual unenhanced images, helping to reduce radiation exposure. The review then provides an update focusing on the advantages of multiparametric magnetic resonance (MR) imaging performance in the histological subtyping of RCC and in the differentiation of benign from malignant renal masses. A proposed standardized stepwise reading of images helps to identify clear cell RCC and papillary RCC with a high accuracy. Contrast-enhanced ultrasound may represent a promising diagnostic tool for the characterization of solid and cystic renal masses. Several combined pharmaceutical imaging strategies using both sestamibi and PSMA offer new opportunities in the diagnosis and staging of RCC, but their role in risk stratification needs to be evaluated. Although radiomics and tumor texture analysis are hampered by poor reproducibility and need standardization, they show promise in identifying new biomarkers for predicting tumor histology, clinical outcomes, overall survival, and the response to therapy. They have a wide range of potential applications but are still in the research phase. Artificial intelligence (AI) has shown encouraging results in tumor classification, grade, and prognosis. It is expected to play an important role in assessing the treatment response and advancing personalized medicine. The review then focuses on recently updated algorithms and guidelines. The Bosniak classification version 2019 incorporates MRI, precisely defines previously vague imaging terms, and allows a greater proportion of masses to be placed in lower-risk classes. Recent studies have reported an improved specificity of the higher-risk categories and better inter-reader agreement. The clear cell likelihood score, which adds standardization to the characterization of solid renal masses on MRI, has been validated in recent studies with high interobserver agreement. Finally, the review discusses the key imaging implications of the 2017 AUA guidelines for renal masses and localized renal cancer.

ctDNA predicts clinical T1a to pathological T3a upstaging after partial nephrectomy

Most patients diagnosed with clear cell renal cell carcinoma (ccRCC) are also detected with small and organ-confined tumors, and the majority of these are classified as clinical tumor stage 1a (cT1a). A considerable proportion of patients with cT1 RCC shows tumor upstaging to pathological stage 3a (pT3a), and these patients have worse oncological outcomes. The role of circulating tumor DNA (ctDNA) in RCC has been limited to monitoring treatment response and resistance. Therefore, the present study aimed to evaluate the potential of ctDNA in predicting pT3a upstaging in cT1a ccRCC. We sequenced plasma samples preoperatively collected from 48 patients who had undergone partial nephrectomy for cT1a ccRCC using data from a prospective cohort RCC. The ctDNA were profiled and compared with clinicopathological ccRCC features to predict pT3a upstaging. Associations between ctDNA, tumor complexity, and pT3a upstaging were evaluated. Tumor complexity was assessed using the anatomical classification system. Univariate analysis used chi-squared and Student's t-tests; multivariate analysis considered significant factors from univariate analyses. Of the 48 patients with cT1a ccRCC, 12 (25%) were upstaged to pT3a, with ctDNA detected in 10 (20.8%), predominantly in patients with renal sinus fat invasion (SFI; n = 8). Among the pT3a group, ctDNA was detected in 75%, contrasting with only 2.8% in patients with pT1a (1/36). Detection of ctDNA was the only significant preoperative predictor of pT3a upstaging, especially in SFI. This study is the first to suggest ctDNA as a preoperative predictor of pT3a RCC upstaging from cT1a based on preoperative radiological images.

Small renal cell carcinoma accompanied by extensive inferior vena cava tumor thrombus diagnosed by percutaneous transvenous biopsy

Introduction

Up to 10% of patients with renal cell carcinoma present with tumor thrombus in the inferior vena cava. We report that a case of small renal cell carcinoma with tumor thrombus extending above the diaphragm for which transvenous biopsy was performed for diagnosis.

Case presentation

A 79-year-old man performed computed tomography to evaluate hepatic dysfunction, which revealed intravenous tumor extending above the diaphragm and a 15-mm-sized exophytic tumor in right kidney. Imaging suggested that the renal tumor was renal cell carcinoma. As this tumor was small and exophytic, confirmation of the intravenous tumor being tumor thrombus associated with renal cell carcinoma was difficult. We simultaneously performed transvenous biopsy on the intravenous tumor and percutaneous biopsy on the renal tumor for obtaining histologic diagnoses. The final diagnosis was small renal cell carcinoma accompanied by tumor thrombus above the diaphragm.

Conclusion

Transvenous biopsy may be useful for the definitive diagnosis of inferior vena cava-tumor thrombus in cases of small renal cell carcinoma.

A Narrative Review on Robotic Surgery as Treatment for Renal Cell Carcinoma with Inferior Vena Cava Thrombus

Renal cell carcinoma (RCC) is a common diagnosis, of which a notable portion of patients present with an extension into the venous circulation causing an inferior vena cava (IVC) tumor thrombus. Venous extension has significant implications for staging and subsequent treatment planning, with recommendations for more aggressive surgical removal, although associated surgical morbidity and mortality is relatively increased. The methods for surgical removal of RCC with IVC thrombus remain complex, particularly surrounding the use of robot-assisted surgery. Robot assistance for radical nephrectomy in this context is recently emerging. Thrombus level has important implications for surgical technique and prognosis. Other preoperative considerations may include location, laterality, size, and wall invasion. The urology literature on treatment of such tumors is largely limited to case series and institutional studies that describe the feasibility of various surgical options for these complex tumors. Further understanding of the outcomes and patient-specific risk factors would shed increased light on the optimal treatment for such cases. This narrative review provides a thorough overview on the previously reported use of robot-assisted nephrectomy in RCC with IVC thrombus to inform further studies which may optimize outcomes and guide shared decision-making.

Growth kinetics of venous tumor thrombus in patients with renal cell carcinoma

INTRODUCTION

Some patients with renal cell carcinoma (RCC) present with venous tumor thrombus (VTT). The extent of the VTT is related to survival, so prompt surgical care is recommended. However, studies evaluating the natural history of VTT in patients with RCC are rare. We sought to evaluate the growth kinetics of VTT in patients with RCC using preoperative cross-sectional images.

MATERIALS AND METHODS

We identified patients who underwent radical nephrectomy and venous tumor thrombectomy at our institution from 01/2009 to 02/2022. We included those with a minimum of 2 adequate preoperative imaging studies (contrast-enhanced Computerized Tomography (CT), noncontrast Magnetic resonance imaging (MRI), or contrast-enhanced MRI), at least 14 days apart. We measured VTT in each study to calculate growth rate, and evaluated predictors of faster growth (demographics, histology, laterality, tumor diameter, and staging). To assess the relation between clinical variables and VTT growth, we used the Wilcoxon Rank-Sum, Kruskal-Wallis, and Spearman correlation tests.

RESULTS

A total of 30 patients were included in the analysis. The median time interval between studies was 33 days. Patients were mostly Caucasian and Males (90% and 70%, respectively). Most patients underwent a CT scan as their initial imaging study (66%), followed with an MRI as second study (73%). The mean venous tumor thrombus growth rate was 0.3 mm/d (standard deviation of 0.5mm), and only rhabdoid/sarcomatoid differentiation showed an association with tumor thrombus growth rate (0.3 vs. 0.63 mm/d, P = 0.038).

CONCLUSIONS

To the best of our knowledge, this is the first study evaluating the natural growth rate of venous tumor thrombus in patients with renal cell carcinoma. We found that tumor thrombi grew an average of 0.3 mm/d (1.0 cm/month) and that those with sarcomatoid and/or rhabdoid differentiation grew faster (0.63 mm/d). Further studies are needed to validate these results and provide a better understanding of tumor thrombus kinetics.

Assessment of Imaging Findings of Renal Carcinoma Subtypes with 3.0T MRI

BACKGROUND

The prevalence of renal masses has escalated as a result of the augmented utilization of cross-sectional imaging techniques. The approach to managing renal masses may exhibit variability contingent upon the subtype of renal cell carcinoma (RCC).

AIM

This research aimed to distinguish between clear cell and papillary RCCs, utilizing dynamic contrast magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

The study assessed the MR images of 112 patients with RCC. Two radiologists independently analyzed tumor size, vascular involvement, signal characteristics in T1- and T2-weighted sequences, the presence of hemosiderin, both microscopic and macroscopic fat content, enhancement patterns, and apparent diffusion coefficient (ADC) values derived from b-values of 1000 s/mm².

RESULTS

Seventy patients had clear cell RCC, and 42 had papillary. In the clear cell RCC, microscopic fat content was significantly higher than the papillary RCC (P < 0.001). However, in papillary RCC, hemosiderin content was substantially greater (P = 0.001). On T2-weighted MR images, clear cell RCCs were usually hyperintense, while papillary RCCs were hypointense (P < 0.001). Even though the rapid enhancement pattern was observed in clear cell RCCs, the progressive enhancement pattern was more prevalent in papillary RCCs (P < 0.001).

CONCLUSION

Hyperintensity on T2-weighted images, microscopic fat content, and rapid enhancement pattern may be indicative of clear cell RCC, whereas hypointensity on T2-weighted images, hemosiderin content, and a progressive contrast pattern may be diagnostic for papillary RCC.

Application of DKI and IVIM imaging in evaluating histologic grades and clinical stages of clear cell renal cell carcinoma

Purpose

To evaluate the value of quantitative parameters derived from diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM) in differentiating histologic grades and clinical stages of clear cell renal cell carcinoma (ccRCC).

Materials and methods

A total of 65 patients who were surgically and pathologically diagnosed as ccRCC were recruited in this study. In addition to routine renal magnetic resonance imaging examination, all patients underwent preoperative IVIM and DKI. The corresponding diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), mean diffusivity (MD), kurtosis anisotropy (KA), and mean kurtosis (MK) values were obtained. Independent-samples t-test or Mann-Whitney U test was used for comparing the differences in IVIM and DKI parameters among different histologic grades and clinical stages. The diagnostic efficacy of IVIM and DKI parameters was evaluated using the receiver operating characteristic (ROC) curve. Spearman's correlation analysis was used to separately analyze the correlation of each parameter with histologic grades and stages of ccRCC.

Results

The D and MD values were significantly higher in low-grade ccRCC than high-grade ccRCC (all p < 0.001) and in low-stage than high-stage ccRCC (all p < 0.05), and the f value of high-stage ccRCC was lower than that of low-stage ccRCC (p = 0.007). The KA and MK values were significantly higher in low-grade than high-grade ccRCC (p = 0.000 and 0.000, respectively) and in low-stage than high-stage ccRCC (p = 0.000 and 0.000, respectively). The area under the curve (AUC) values of D, D*, f, MD, KA, MK, DKI, and IVIM+DKI values were 0.825, 0.598, 0.626, 0.792, 0.750, 0.754, 0.803, and 0.857, respectively, in grading ccRCC and 0.837, 0.719, 0.710, 0.787, 0.796, 0.784, 0.864, 0.823, and 0.916, respectively, in staging ccRCC. The AUC of IVIM was 0.913 in staging ccRCC. The D, D*, and MD values were negatively correlated with the histologic grades and clinical stages (all p < 0.05), and the KA and MK values showed a positive correlation with histologic grades and clinical stages (all p < 0.05). The f value was also negatively correlated with the ccRCC clinical stage (p = 0.008).

Conclusion

Both the IVIM and DKI values can be used preoperatively to predict the degree of histologic grades and stages in ccRCC, and the D and MD values have better diagnostic performance in the grading and staging. Also, further slightly enhanced diagnostic efficacy was observed in the model with combined IVIM and DKI parameters.

Cohort profile - the Renal cell cancer: Lifestyle, prognosis and quality of life (ReLife) study in the Netherlands

PURPOSE

The Renal cell cancer: Lifestyle, prognosis and quality of life (ReLife) study is set up to obtain insight into the association of patient and tumour characteristics, lifestyle habits and circulating biomarkers with body composition features in patients with localised renal cell cancer (RCC). Further, it aims to assess the association of body composition features, lifestyle habits and circulating biomarkers with clinical outcomes, including health-related quality of life.

PARTICIPANTS

The ReLife study is a multicentre prospective cohort study involving 368 patients with newly diagnosed stages I-III RCC recruited from January 2018 to June 2021 from 18 hospitals in the Netherlands. At 3 months, 1 year and 2 years after treatment, participants fill out a general questionnaire and questionnaires about their lifestyle habits (eg, diet, physical activity, smoking and alcohol consumption), medical history and health-related quality of life. At all three time points, patients wear an accelerometer and have blood samples taken. CT scans for body composition analysis are being collected. Permission is asked for collection of tumour samples. Information about disease characteristics, treatment of the primary tumour and clinical outcomes is being collected from medical records by the Netherlands Cancer Registry.

FINDINGS TO DATE

A total of 836 invited patients were eligible and 368 patients were willing to participate and were included (response rate 44%). The mean age of patients was 62.5±9.0 years and 70% was male. The majority had stage I (65%) disease and were treated with radical nephrectomy (57%). Data collection at 3 months and 1 years after treatment have been finalised.

FUTURE PLANS

Data collection at 2 years after treatment is expected to be finalised in June 2023 and longitudinal clinical data will continue to be collected. Results of studies based on this cohort are important to develop personalised evidence-based lifestyle advice for patients with localised RCC to enable them to get more control over their disease course.

Performance of clear cell likelihood scores in characterizing solid renal masses at multiparametric MRI: an external validation study

PURPOSE

The purpose of this study is to evaluate the accuracy and interobserver agreement of ccLS in diagnosing clear cell renal cell carcinoma (ccRCC).

METHODS

This retrospective single-center study evaluated consecutive patients with solid renal masses who underwent mpMRI followed by percutaneous biopsy and/or surgical excision between January 2010 and December 2020. Predominantly (> 75%) cystic masses, masses with macroscopic fat and infiltrative masses were excluded. Two abdominal radiologists independently scored each renal mass according to the proposed ccLS algorithm. The diagnostic performance of ccLS categories for ccRCC was calculated using logistic regression modeling. Diagnostic accuracy for predicting ccRCC was calculated using 2 × 2 contingency tables. Interobserver agreement for ccLS was evaluated with Cohen's k statistic.

RESULTS

A total of 79 patients (mean age, 63 years ± 12 [SD], 50 men) with 81 renal masses were evaluated. The mean size was 36 mm ± 28 (range 10-160). Of the renal masses included, 44% (36/81) were ccRCC. The area under the receiver operating characteristic curve was 0.87 (95% CI 0.79-0.95). Using ccLS ≥ 4 to diagnose ccRCC, the sensitivity, specificity, and positive predictive value were 93% (95% CI 79, 99), 63% (95% CI 48, 77), and 67% (95% CI 58, 75), respectively. The negative predictive value of ccLS ≤ 2 was 93% (95% CI 64, 99). The proportion of ccRCC by ccLS category 1 to 5 were 10%, 0%, 10%, 57%, and 84%, respectively. Interobserver agreement was moderate (k = 0.47).

CONCLUSION

In this study, clear cell likelihood score had moderate interobserver agreement and resulted in 96% negative predictive value in excluding ccRCC.

The role of cytoreductive nephrectomy and systemic therapy in the management of tumour thrombus in patients with metastatic renal cell carcinoma

BACKGROUND

Outcomes for patients with metastatic renal cell carcinoma (mRCC) and tumour thrombus remain poor. Recent data suggest limited role for cytoreductive nephrectomy (CN) and data on thrombus response to systemic therapy (ST) is scarce. Here, we describe response and survival of patients with de novo mRCC and thrombi treated with ST with or without CN.

METHODS

Demographics, disease characteristics and survival of patients with de novo mRCC were collected. Progression-free survival (PFS) and overall survival (OS) in months (m) was calculated using the Kaplan-Meier method (log-rank).

RESULTS

Between 2002 and 2019, 226 patients with mRCC were identified, 64 (28.3%) had tumour thrombus out of which 18 (28.1%) received only ST. Among 12 evaluable patients, thrombus response, stability and progression were seen in 3 (25%), 6 (50%) and 3 (25%) patients, respectively. Median OS was similar for patients with and without tumour thrombus treated with systemic therapy alone [OS: 12.1 m (8.8-27.7) vs. 13.9 m (7.9-21.5), p = 0.87]. CN predicted for better OS in patients with tumour thrombus [OS: 29.4 m (17.4-48.9) vs. 12.1 m (8.8-27.7), p = 0.01].

CONCLUSION

In this retrospective series of patients with mRCC and tumour thrombus, addition of CN to ST improved outcomes. Validation of these findings with contemporary regimens is needed.

Patency outcomes of primary inferior vena cava repair in radical nephrectomy and tumor thrombectomy

OBJECTIVE

The reconstruction of inferior vena cava (IVC) during radical nephrectomy and venous tumor thrombectomy (RN-VTT) is mostly performed with primary repair or with a patch/graft. We sought to systematically evaluate the outcomes of IVC patency over short- to intermediate-term follow-up for patients undergoing primary repair of IVC and to assess the association with survival.

METHODS

A retrospective review of patients undergoing RN-VTT between January 2013 and August 2018 was conducted. Patients were followed until death, last available follow-up, or March 2022. The patency outcomes and IVC diameters were studied using follow-up cross-sectional imaging. The χ² test, Student t test, and Kaplan-Meier survival analysis were used.

RESULTS

Seventy-seven patients were included. The mean age was 59.2 ± 12.2 years and 45.4% had Mayo classification level III thrombus or higher. At a median follow-up of 36.5 months (13.3-60.7 months), the 3-year overall survival (OS) was 64%. Sixty patients underwent primary repair of the IVC and 48 of these patients were assessed for IVC patency. Ten patients (20.8%) developed caval occlusion, either from recurrent tumor (8.3%), new-onset bland thrombus (8.3%), or stenosis (4.2). The IVC patency seemed to be a significant predictor of OS (hazard ratio, 2.85; P = .021). Although the IVC diameters decreased significantly at the 3-month postoperative scan at the infrarenal (P = .019), renal (P < .001), and suprarenal (P < .001) levels, they did not decrease further on long-term follow-up imaging.

CONCLUSIONS

IVC reconstruction with primary repair results in an overall patency rate of 80.2% with only a 4.0% rate of stenosis. Recurrence of tumor thrombus (8.3%) or bland thrombus (8.3%) are the predominant reasons for IVC occlusion after RN-VTT, and this outcome is associated with poor OS.

Selective parenchymal clamping in open partial nephrectomy: Early experience with a low cost, reusable novel parenchymal clamp

Objectives

The objective of this study is to present our initial experience with a novel parenchymal clamp (NPC) developed to allow partial nephrectomies (PN) to be performed without whole kidney ischaemia. We compare patients who underwent PN with the NPC with those undergoing standard PNs.

Methods

The NPC applies pressure only to the portion of the parenchyma containing the small renal mass (≤3.5 cm) and interrupts regional blood flow.A retrospective analysis was conducted on patients that underwent open PN within our unit. Minimum follow-up was 12 months. Patient and disease characteristics, perioperative outcomes and renal function estimated Glomerular Filtration Rate (eGFR) were compared.

Results

Data were collected on 63 patients, of whom 33 had their procedure performed with the NPC. Demographic characteristics and comorbidity profiles were not significantly different between groups (p between 1.0 and 0.08). RENAL nephrometry scores were 5.6 in the NPC group versus 6.2 in the standard PN group (p = 0.146).Perioperative, operative and postoperative data did not show significant differences. There was no difference in the rates of Clavien-Dindo III or above complications between the two groups (NPC 3/33 vs. standard PN 5/30, p = 0.416). There was also no statistically significant difference to changes in renal functional at 12 months (change -5.2 and -6.4, p = 0.712).

Conclusions

Despite the limited sample size and follow-up, this study establishes the safety of the NPC. In the future, we intend to perform a prospective study on the laparoscopic version.

Systematic review and meta-analysis of multiparametric MRI clear cell likelihood scores for classification of small renal masses

Purpose

To systematically assess the multiparametric MRI clear cell likelihood score (ccLS) algorithm for the classification of small renal masses (SRM).

Methods

We conducted an electronic literature search on Web of Science, MEDLINE (Ovid and PubMed), Cochrane Library, EMBASE, and Google Scholar to identify relevant articles from 2017 up to June 30, 2022. We included studies reporting the diagnostic performance of the ccLS for characterization of solid SRM. The bivariate model and hierarchical summary receiver operating characteristic (HSROC) model were used to pool sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR−), and diagnostic odds ratio (DOR). The quality evaluation was performed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

Results

A total of 6 studies with 825 renal masses (785 patients) were included in the current meta-analysis. The pooled sensitivity and specificity for cT1a renal masses were 0.80 (95% CI 0.75–0.85) and 0.74 (95% CI 0.65–0.81) at the threshold of ccLS ≥4, the pooled LR+, LR−, and DOR were 3.04 (95% CI 2.34-3.95), 0.27 (95% CI 0.22–0.33), and 11.4 (95% CI 8.2-15.9), respectively. The area under the HSROC curve was 0.84 (95% CI 0.81–0.87). For all cT1 renal masses, the pooled sensitivity and specificity were 0.80 (95% CI 0.74–0.85) and 0.76 (95% CI 0.67–0.83).

Conclusions

The ccLS had moderate to high accuracy for identifying ccRCC from other RCC subtypes and with a moderate inter-reader agreement. However, its diagnostic performance remain needs multi-center, large cohort studies to validate in the future.

Diagnostic performance of the Bosniak classification, version 2019 for cystic renal masses: A systematic review and meta-analysis

Purpose

To systematically assess the diagnostic performance of the Bosniak classification, version 2019 for risk stratification of cystic renal masses.

Methods

We conducted an electronic literature search on Web of Science, MEDLINE (Ovid and PubMed), Cochrane Library, EMBASE, and Google Scholar to identify relevant articles between June 1, 2019 and March 31, 2022 that used the Bosniak classification, version 2019 for risk stratification of cystic renal masses. Summary estimates of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR−), and diagnostic odds ratio (DOR) were pooled with the bivariate model and hierarchical summary receiver operating characteristic (HSROC) model. The quality of the included studies was assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

Results

A total of eight studies comprising 720 patients were included. The pooled sensitivity and specificity were 0.85 (95% CI 0.79–0.90) and 0.68 (95% CI 0.58–0.76), respectively, for the class III/IV threshold, with a calculated area under the HSROC curve of 0.84 (95% CI 0.81–0.87). The pooled LR+, LR−, and DOR were 2.62 (95% CI 2.0–3.44), 0.22 (95% CI 0.16–0.32), and 11.7 (95% CI 6.8–20.0), respectively. The Higgins I² statistics demonstrated substantial heterogeneity across studies, with an I² of 57.8% for sensitivity and an I² of 74.6% for specificity. In subgroup analyses, the pooled sensitivity and specificity for CT were 0.86 and 0.71, respectively, and those for MRI were 0.87 and 0.67, respectively. In five studies providing a head-to-head comparison between the two versions of the Bosniak classification, the 2019 version demonstrated significantly higher specificity (0.62 vs. 0.41, p < 0.001); however, it came at the cost of a significant decrease in sensitivity (0.88 vs. 0.94, p = 0.001).

Conclusions

The Bosniak classification, version 2019 demonstrated moderate sensitivity and specificity, and there was no difference in diagnostic accuracy between CT and MRI. Compared to version 2005, the Bosniak classification, version 2019 has the potential to significantly reduce overtreatment, but at the cost of a substantial decline in sensitivity.

Artificial Intelligence in Kidney Cancer

Artificial intelligence is rapidly expanding into nearly all facets of life, particularly within the field of medicine. The diagnosis, characterization, management, and treatment of kidney cancer is ripe with areas for improvement that may be met with the promises of artificial intelligence. Here, we explore the impact of current research work in artificial intelligence for clinicians caring for patients with renal cancer, with a focus on the perspectives of radiologists, pathologists, and urologists. Promising preliminary results indicate that artificial intelligence may assist in the diagnosis and risk stratification of newly discovered renal masses and help guide the clinical treatment of patients with kidney cancer. However, much of the work in this field is still in its early stages, limited in its broader applicability, and hampered by small datasets, the varied appearance and presentation of kidney cancers, and the intrinsic limitations of the rigidly structured tasks artificial intelligence algorithms are trained to complete. Nonetheless, the continued exploration of artificial intelligence holds promise toward improving the clinical care of patients with kidney cancer.

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.

[Risk factors of renal sinus invasion in clinical T1 renal cell carcinoma patients undergoing nephrectomy]

OBJECTIVE

To summarize the clinicoradiological characteristics of clinical T1 renal cell carcinoma patients and to investigate the risk factors of renal sinus invasion in cT1 renal cell carcinoma patients undergoing nephrectomy.

METHODS

A retrospective study was conducted in cT1 renal cell carcinoma patients from January 2016 to August 2019 in Department of Urology, Peking University Third Hospital, who underwent partial or radical nephrectomy by analyzing clinicopathological and radiological data. The influencing factors of renal sinus invasion for cT1 renal cell carcinoma were determined by χ² test, Mann-Whitney U test and Logistic regression analysis.

RESULTS

A total of 507 patients were enrolled, including 354 males (69.8%) and 153 females (30.2%). The median age was 59 years and the median body mass index (BMI) was 25.5 kg/m². Eighteen patients (3.6%) had gross hematuria preoperatively. The median tumor diameter was 3.5 cm. Three hundred twenty-two patients (63.5%) were staged clinical T1a and 165 cases (36.5%) were staged clinical T1b. The median R.E.N.A.L. score was 8. Three hundred fifty-nine patients (70.8%) had regular tumor border and 148 (29.2%) irregular. All the patients underwent surgical treatment, including 186 (36.7%) partial nephrectomy and 321 (63.3%) radical nephrectomy. Postoperative pathology showed seventy-five patients (14.8%) had renal sinus invasion, including 18 in cT1a (5.6%) and 57 in cT1b (30.8%). Univariate analysis showed that age (P=0.020), R.E.N.A.L. score (R value, E value, N value, P < 0.001) and tumor border (P < 0.001) were associated risk factors for cT1 renal cell carcinoma with renal sinus invasion. On multivariate binary Logistic analysis, R.E.N.A.L. score (P≤0.020) and irregular tumor border (P=0.001) were independent risk factors.

CONCLUSION

For cT1 renal cell carcinoma patients undergoing nephrectomy, about 15% had renal sinus invasion postoperatively. High R.E.N.A.L. score and irre-gular tumor border help predicting cT1 renal cell carcinoma renal sinus invasion.

Current Trends in Management of Renal Cell Carcinoma with Venous Thrombus Extension

PURPOSE OF REVIEW

To review the evidence regarding the current trends in surgical management of renal cell carcinoma (RCC) with inferior vena cava (IVC) thrombosis. Recent published series have shown the role of minimally invasive surgery in IVC thrombectomy. This review article evaluates the present RCC with venous extent literature to assess the role of open and minimally invasive surgery in this scenario.

RECENT FINDINGS

Robotic urological surgery has shown to have known benefits in radical prostatectomy, partial nephrectomy, and pyeloplasty. Recent published series showed feasibility of robotic IVC thrombectomy even for level IV cases. With growing number of robot-assisted and laparoscopic surgeries worldwide, there is a current tendency to treat this complex and challenging pathology with a minimally invasive approach, without compromising oncological outcomes.

[Criteria for an improved prognostic stratification in category pT renal carcinoma]

Asymptomatic renal carcinomas are usually small and localized and thus, for the assessment of pT, precise criteria are required, able to identify the initial phases of a local extension and correlate them with current prognostic prospects. Various studies and consensus meetings have defined precisely how to measure tumoral nodules (solid, cystic and multiple). Furthermore, they have distinguished tumoral extension to the renal sinus, which has a worse prognosis, from that to the perirenal adipose tissue. They have also analyzed the clinical significance of invasion of the sinus vessels, the hilar veins and parenchymal vascular retroinvasion. Our aim is to revise and update the criteria of the different pT subcategories and consider those morphological aspects which could be clinically significant and that are not currently included in the TNM classification.

Differential diagnosis of hypervascular ultra-small renal cell carcinoma and renal angiomyolipoma with minimal fat in early stage by using thin-section multidetector computed tomography

PURPOSE

The purpose of this study was to investigate the difference between imaging features of ultra-small renal cell carcinoma (usRCC) and angiomyolipoma with minimal fat (mfAML) whose enhancement were both hypervascular by using multidetector computed tomography (MDCT).

MATERIALS AND METHODS

Confirmed by pathology, 40 cases of hypervascular usRCC and 21 cases of hypervascular mfAML both with diameter of 2 cm or less were compared and analyzed retrospectively, including traditional imaging features and thin-section computed tomography (CT) dynamic enhanced parameters. Meanwhile, receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic efficacy of each significant parameter and the information with diagnostic value was selected to construct the prediction model.

RESULTS

Comparison of traditional imaging features: the features, included age, shape, location, central location of tumor, wedge sign, renal cortex lift sign, black star sign, enhanced homogeneity in cortical phase (CP) and enhancement pattern had no significant difference between usRCC and mfAML (P > 0.05); sex, cystic degeneration or necrosis, pseudocapsule sign, and enhanced homogeneity in nephrographic phase (NP) had significant differences between usRCC and mfAML (P < 0.05). Comparison of CT dynamic enhanced parameters: the CT value, NEV and REV of usRCC were all higher than mfAML in both CP and NP (P < 0.01). Respectively, the area under the ROC curve (AUC) were 0.74, 0.75, 0.78, 0.83, 0.81 and 0.78. The sensitivity and specificity for differentiating ucRCC from mfAML were 85.0% and 76.2% respectively when NEV_NP was 73.6 HU as the critical value. Multivariate analysis showed that male, cystic degeneration or necrosis, and NEV_NP higher than 73.6 HU as an independent risk factor for usRCC (P < 0.01). The AUC value of the prediction model constructed by the combination was 0.94, the accuracy was 86.89%, the sensitivity was 82.50%, and the specificity was 95.24%.

CONCLUSION

Morphological characteristics in traditional diagnosis of small renal carcinoma (diameter of 4 cm or less) have certain significance in differentiating hypervascular usRCC and mfAML in early stage, but the diagnostic efficacy was limited. Sex, cystic degeneration or necrosis, and quantitative parameters measured after enhancement play an important role in differential diagnosis of hypervascular usRCC and mfAML, and the prediction model constructed by the combination has a good diagnostic performance.

Challenges of early renal cancer detection: symptom patterns and incidental diagnosis rate in a multicentre prospective UK cohort of patients presenting with suspected renal cancer

OBJECTIVES

To describe the frequency and nature of symptoms in patients presenting with suspected renal cell carcinoma (RCC) and examine their reliability in achieving early diagnosis.

DESIGN

Multicentre prospective observational cohort study.

SETTING AND PARTICIPANTS

Eleven UK centres recruiting patients presenting with suspected newly diagnosed RCC. Symptoms reported by patients were recorded and reviewed. Comprehensive clinico-pathological and outcome data were also collected.

OUTCOMES

Type and frequency of reported symptoms, incidental diagnosis rate, metastasis-free survival and cancer-specific survival.

RESULTS

Of 706 patients recruited between 2011 and 2014, 608 patients with a confirmed RCC formed the primary study population. The majority (60%) of patients were diagnosed incidentally. 87% of patients with stage Ia and 36% with stage III or IV disease presented incidentally. Visible haematuria was reported in 23% of patients and was commonly associated with advanced disease (49% had stage III or IV disease). Symptomatic presentation was associated with poorer outcomes, likely reflecting the presence of higher stage disease. Symptom patterns among the 54 patients subsequently found to have a benign renal mass were similar to those with a confirmed RCC.

CONCLUSIONS

Raising public awareness of RCC-related symptoms as a strategy to improve early detection rates is limited by the fact that related symptoms are relatively uncommon and often associated with advanced disease. Greater attention must be paid to the feasibility of screening strategies and the identification of circulating diagnostic biomarkers.

Survival Analysis of Pathological T3a Upstaging in Clinical T1 Renal Cell Carcinoma

AIM

To evaluate the oncological outcomes of pathological T3a upstaging from clinical T1 renal cell carcinoma.

PATIENTS AND METHODS

We retrospectively studied patients who underwent radical or partial nephrectomy for clinical T1 renal tumors.

RESULTS

The median follow-up period was 44 months. At three and five years, the respective overall survival rate was 88.7% and 82.4% in pT3a disease, 95.7% and 93.4% in pT1 (p=0.008), the cancer-specific survival rate, 93.9% and 90.8% in pT3a, 99% and 97.7% in pT1 (p=0.001), and the recurrence-free survival rate, 79.7% and 71.0% in pT3a, and 95.5 and 94.3% in pT1 (p<0.001).

CONCLUSION

Patients with pathological T3a upstaging tumors were associated with a significantly decreased survival rate, along with a higher recurrence rate when compared to those with pathological T1 disease.

Prognostic significance of the sub-classification of stage pT3a renal tumors by perinephric and sinus fat invasion

In the current Tumor-Node-Metastasis (TNM) classification system for renal cell carcinoma (RCC), both perinephric fat invasion (PFI) and renal sinus fat invasion (SFI) are classified at the T3a stage. However, their associated prognoses are clinically controversial. The present study proposes a new sub-classification criterion for pathological T3a (pT3a) RCC with SFI or PFI to resolve this dispute. Data were collected from consecutive records of 2,765 patients with T1a renal cancer, who had undergone partial nephrectomy (PN) between 2001 and 2015 at one of four hospitals. Among these patients, 127 cases were diagnosed with stage pT3a RCC with SFI or PFI, according to final pathological examination. The pathological characteristics, clinical data and follow-up observations were analyzed. Of the 127 patients, with an average follow-up duration of 56 months (range, 15–60 months), 17 cases of tumor recurrence were found. After analysis of the pathological findings, the following new sub-classification criteria was proposed for pT3a RCC with SFI or PFI: i) Type A, renal tumor invades the pseudo-capsule and contacts with the perinephric adipose tissues directly (3 recurrences out of 57 patients); ii) type B, tumor protrudes into the perinephric adipose tissues like a tongue (4 recurrences out of 29 patients); and iii) type C, tumor nodules distribute in perinephric adipose tissues (10 recurrences out of 41 patients). There was statistically significant difference between the three subtypes in terms of recurrence rate (P=0.023). In conclusion, controversies remain in the current TNM classification system for pT3a RCC. The present study added to the available data and found that pT3a RCC with tumor nodules in perinephric adipose or/and with an irregular tumor protruding into adipose tissues showed a higher recurrence rate. Thus, it is recommended that pT3a RCC should be carefully analyzed and should be considered differently to other stages of RCC.

Evaluation of the MR and pathology characteristics immediately following percutaneous MR-guided microwave ablation in a rabbit kidney VX2 tumor implantation model

Purpose: This study aimed to evaluate the immediate efficacy of magnetic resonance (MR)-guided microwave ablation (MWA) in rabbit kidneys implanted with VX2 tumors.Materials and methods: MR-guided MWA was performed in eight VX2 tumor-bearing rabbits. MR images after ablation were obtained and analyzed. The differences between the tissue specimens and MR images obtained after ablation were compared.Results: On the three-dimensional volumetric interpolated breath-hold T1-weighted (3D-VIBE-T1WI) sequence, a low signal intensity indicated the primary tumor at the center of the ablation area, which was surrounded by a peripheral high-signal area. The signal for the primary tumor in the fast spin-turbo spin-echo T2-weighted (FS-TSE-T2WI) sequence was lower than before, and the ablation zone showed a low signal that completely covered the primary tumor. There was no significant difference in volume among the low-signal areas of the primary tumor on FS-TSE-T2WI before MWA, the central low-signal area on 3D-VIBE-T1WI after MWA, and the tumor coagulation necrosis area on the tissue specimens (p > 0.05). No significant difference was found in the volume of ablation zones among the tissue specimens, the high-signal area around the lesion on the 3D-VIBE-T1WI sequence, and the low-signal area covering the lesion on the FS-TSE-T2WI sequence (p > 0.05).Conclusion: Magnetic resonance imaging (MRI) is an effective method for immediate efficacy evaluation of rabbit renal VX2 tumors after MWA and can serve as a valuable reference for the clinical assessment of post-ablative renal tumors.

Utilization and Operative Influence of Renal Mass Biopsy in the Small Renal Mass: Analysis from the Clinical Research Office of the Endourological Society Small Renal Mass registry

Introduction and Objective: Definitive inclusion of renal mass biopsy (RMB) in small renal mass (SRM) diagnostic algorithm remains controversial. We assessed incidence and accuracy of RMB in SRMs in the CROES Renal Mass registry and the influence of preoperative RMB on perioperative complications after SRM nephron-sparing surgery (NSS). Materials and Methods: "ad hoc" description of incidence of preoperative RMB and characteristics of SRM cases with and without RMB. Accuracy of RMB was calculated in the SRM subcohort that received extirpative treatment and complication rate after NSS compared to between the two groups. Continuous variables were compared using t-test; categorical variables were compared using the chi-square test. K-statistics was used to analyze agreement between the biopsy histology and surgical pathology. Logistic regression was used to assess the association between RMB and NSS complications. All tests were two sided, and p-values <0.05 were considered statistically significant. Results: The rate of preoperative RMB in SRMs was 11.6% (175/1597) in Europe and the United States. RMB patients were more likely to have hypertension (p < 0.04), be on dialysis (p < 0.024), or smokers (p = 0.005), with multiple/bilateral tumors (0.008 and 0.010) and previous other malignancy (p = 0.021). They underwent radical nephrectomy more frequently than non-RMB group (p = 0.034). RMB was nondiagnostic in 16 cases (9%). Accuracy of RMB in distinguishing malignant from benign was 89.5%. Agreement between biopsy and final surgical pathology was 93% for malignant vs benign tumors (kappa = 0.655). Upstaging to pT3a occurred more frequently in the RMB group (12.6% vs 6.25% [p = 0.022]). Complication rate in renal mass-NSS subcohort was 15.8%, not statistically different between RMB and non-RMB groups. On logistic regression analysis, RMB was not associated with increased risk of postoperative complication after NSS (OR: 0.9, 95% CI: 0.43-1.89). Conclusion: The practice of RMB in SRM is still scarce despite high accuracy and concordance with final pathology. RMB does not seem to increase complication rate after NSS.

Antioxidants as Renoprotective Agents for Ischemia during Partial Nephrectomy

Small renal masses have been diagnosed increasingly in recent decades, allowing surgical treatment by partial nephrectomy. This treatment option is associated with better renal function preservation, in comparison with radical nephrectomy. However, for obtaining a bloodless field during surgery, occlusion of renal artery and veins is often required, which results in transitory ischemia. The renal ischemia-reperfusion injury is associated with increased reactive oxygen species production leading to renal tissue damage. Thus, the use of antioxidants has been advocated in the partial nephrectomy perioperative period. Several antioxidants were investigated in regard to renal ischemia-reperfusion injury. The present manuscript aims to present the literature on the most commonly studied antioxidants used during partial nephrectomy. The results of experimental and clinical studies using antioxidants during partial nephrectomy are reported. Further, alimentary sources of some antioxidants are presented, stimulating future studies focusing on perioperative antioxidant-rich diets.

A Deep Learning-Based Radiomics Model for Differentiating Benign and Malignant Renal Tumors

OBJECTIVES: To investigate the effect of transfer learning on computed tomography (CT) images for the benign and malignant classification on renal tumors and to attempt to improve the classification accuracy by building patient-level models. METHODS: One hundred ninety-two cases of renal tumors were collected and identified by pathologic diagnosis within 15 days after enhanced CT examination (66% male, 70% malignant renal tumors, average age of 62.27 ± 12.26 years). The InceptionV3 model pretrained by the ImageNet dataset was cross-trained to perform this classification. Five image-level models were established for each of the Slice, region of interest (ROI), and rectangular box region (RBR) datasets. Then, two patient-level models were built based on the optimal image-level models. The network's performance was evaluated through analysis of the receiver operating characteristic (ROC) and five-fold cross-validation. RESULTS: In the image-level models, the test results of model trained on the Slice dataset [accuracy (ACC) = 0.69 and Matthews correlation coefficient (MCC) = 0.45] were the worst. The corresponding results on the ROI dataset (ACC = 0.97 and MCC = 0.93) were slightly better than those on the RBR dataset (ACC = 0.93 and MCC = 0.85) when freezing the weights before the mixed6 layer. Compared with the image-level models, both patient-level models could discriminate better (ACC increased by 2%-5%) on the RBR and Slice datasets. CONCLUSIONS: Deep learning can be used to classify benign and malignant renal tumors from CT images. Our patient-level models could benefit from 3D data to improve the accuracy.

Imaging Advances in the Management of Kidney Cancer

New developments in cross-sectional imaging, including contrast-enhanced ultrasound, dual-energy computed tomography, multiparametric magnetic resonance imaging, single-photon emission computed tomography, and positron emission tomography, together with novel application of existing and novel radiotracers, have changed the landscape of renal mass characterization (ie, virtual biopsy) as well as the detection of metastatic disease, prognostication, and response assessment in patients with advanced kidney cancer. A host of imaging response criteria have been developed to characterize the response to targeted and immune therapies and correlate with patient outcomes, each with strengths and limitations. Recent efforts to advance the field are aimed at increasing objectivity with quantitative techniques and the use of banks of imaging data to match the vast genomic data that are becoming available. The emerging field of radiogenomics has the potential to transform further the role of imaging in kidney cancer management through eventual noninvasive characterization of the tumor histology and genetic microenvironment in single renal masses and/or metastatic disease. We review of the effect of currently available imaging techniques in the management of patients with kidney cancer, including localized, locally advanced, and metastatic disease.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Declining incidence of benign lesions among small renal masses treated with surgery: Effect of diagnostic tests for characterization

PURPOSE

We evaluated the changes in the incidence of benign lesions in surgically removed small renal masses (SRMs) and the effect of diagnostic tests for characterizing SRMs.

METHODS

We included 2,707 patients receiving surgery for SRMs (<4cm). Trends in the incidence of benign histology were evaluated according to the surgery year (period 1: 2001-2005, 2: 2006-2010, and 3: 2011-2015). Multivariable logistic regression analysis was performed to identify factors associated with benign lesions. Additionally, the number of surgeries prevented due to benign histological findings on renal mass biopsies (RMB) done on 206 patients with SRM during study period was evaluated.

RESULTS

Benign histology was identified in 192 (7.1%) patients. Incidence of benign histology was 9.7%, 7.0%, and 6.3% for period 1, 2 and 3, respectively. The uses of multiphase computed tomography and magnetic resonance imaging were more common in periods 2 and 3 than in period 1 (P<0.001). The use of RMB in period 3 was higher than in periods 1 and 2 (0.8 vs. 0.9 vs. 9.0%, P<0.001). In multivariable analysis, older age, male sex, larger tumor size, and recent surgery year (period 3 vs. 1, odds ratio = 0.62, P = 0.028) were independently associated with decreased odds of benign lesions. The number of prevented surgeries by performing RMB was 0, 10, and 39 in periods 1, 2, and 3, respectively.

CONCLUSIONS

Incidence of benign histology after surgery for SRMs declined during recent years, which might be associated with the recent increased use of RMB.

Volume and Shape Assessment of Renal Radiofrequency Ablation Lesion

OBJECTIVE

To evaluate the microscopic characteristics and quantify the volume of a radiofrequency ablation (RFA) lesion.

METHODS

Ten male pigs were submitted to laparoscopic RFA. An RFA needle was introduced in the lower pole of the left kidney to create a lesion expected to be a sphere of 2.0 cm diameter. The animals were followed up for 21 days. Kidneys were weighed and the volume was assessed using Scherle's method. Cavalieri's principle was used to assess the RFA volume, and sphericity was calculated to assess RFA lesion. One sample t test was used to compare RFA volume with the volume of a sphere of 2.0 cm diameter, and sphericity to hypothetical values of a sphere and an icosahedron. Fragments of RFA region were histologically evaluated.

RESULTS

Three animals developed postoperative complications and were excluded from the analyses. There was no difference in the mean weight and volume between right and left kidneys following RFA. The mean total volume of RFA injury was 3.44 cm³. There was no difference in the RFA volume in comparison with hypothetical volumes of a sphere and an icosahedron of 2.0 cm diameter. Sphericity of the RFA injury was not similar with a sphere; however, it was similar to an icosahedron. Histology revealed areas of coagulation necrosis, fibrosis, and inflammatory mononuclear infiltration. Areas with normal tissue were also observed.

CONCLUSION

The volume of injury caused by RFA was as expected and its shape was comparable with an icosahedron. Microscopic evaluation revealed areas of normal-appearing tissue.

Decisional Quality in Patients With Small Renal Masses

OBJECTIVE

To measure decisional quality in patients being counseled on treatment for small renal masses and identify potential areas of improvement.

MATERIALS AND METHODS

A total of 73 patients diagnosed with small renal masses at the University of California, Los Angeles Health completed an instrument measuring decisional conflict, patient satisfaction with care, disease-specific knowledge, and patient impression that shared decision-making occurred in the visit after counseling by a specialist. Participant characteristics were compared between those with high and low decisional conflict using chi-square or Student t test (or Wilcoxon rank-sum test).

RESULTS

Participants were mostly older (mean age 63.5), white (84%), in a relationship (61%), and unemployed or retired (63%). Mean knowledge score was 59% correct. The mean (standard deviation) decisional conflict score was 16.4 (18.4) indicating low levels of decisional conflict but with a wide range of scores. Comparing participants with high decisional conflict with those with low decisional conflict, there were significant differences in knowledge scores (Wilcoxon P = .0069), patient satisfaction with care (P = .0011), and perceived shared decision-making (P <.0001).

CONCLUSION

Patients with small renal masses generally have low levels of decisional conflict and can identify a preferred treatment after a physician visit. However, both groups lack overall knowledge about their disease even after counseling, and thus may be heavily influenced by paternalistic care. Those patients with decisional conflicts are less likely to perceive their care as satisfactory and are less likely to be involved in decision-making.

Evaluation and management of a large incidentally discovered renal mass

Increasingly, renal cell cancer is diagnosed because of an incidental finding of a renal mass on an imaging study. Incidentally discovered masses are more likely to be small and, if malignant, represent localized renal cell cancer. The imaging features of the tumor and patient characteristics inform the management options, which favor a nephron-sparing approach over radical nephrectomy. Clinical stage at the time of diagnosis has important prognostic implications for the patient. This article reviews the presentation, diagnostic evaluation, and management of an incidentally discovered renal mass.

Imaging and Screening of Kidney Cancer

Renal cell carcinoma (RCC) exhibits a diverse and heterogeneous disease spectrum, but insight into its molecular biology has provided an improved understanding of potential risk factors, oncologic behavior, and imaging features. Computed tomography (CT) and MR imaging may allow the identification and preoperative subtyping of RCC and assessment of a response to various therapies. Active surveillance is a viable management option in some patients and has provided further insight into the natural history of RCC, including the favorable prognosis of cystic neoplasms. This article reviews CT and MR imaging in RCC and the role of screening in selected high-risk populations.

Glomerular Loss After Renal Radiofrequency Ablation Are Comparable to 30 Minutes of Warm Ischemia

PURPOSE

To compare, with stereological methods, the glomerular loss in kidneys submitted to radiofrequency ablation (RFA) or warm ischemia.

MATERIALS AND METHODS

Twenty-six male pigs were divided into three groups. Eight animals were allocated in the sham group, which was submitted to laparoscopic dissection of the left renal hilum, without renal ischemia. Eight animals were allocated in the ischemia group, which had the left renal hilum clamped for 30 minutes under laparoscopic access. Ten animals were submitted to RFA of the left kidney lower pole, under laparoscopic visualization. Animals were euthanized 21 days after surgery, when kidneys were collected. Fragments of the upper pole of the left kidney were processed for morphometric analysis. Right kidney was used as self-controls for each animal. Glomerular volumetric density (Vv[glom]); volume-weighted glomerular volume (VWGV); and glomerular density were quantified by stereological methods and compared by Student's t-test and one-way-analysis of variance with Dunnett's post-test.

RESULTS

Three animals in the RFA group developed postoperative complications (Urinoma/Hydronephrosis) and were excluded from the analysis. No difference was found among the kidneys submitted to RFA and warm ischemia for all parameters. However, these kidneys showed lower Vv[glom] and glomerular density when compared to its self-controls (right kidneys), and when compared to sham-operated animals (p < 0.05). No difference was observed in regards to VWGV among the groups.

CONCLUSION

RFA in pigs determines a significant reduction of glomerular density in the remaining parenchyma. This alteration was comparable to that observed in kidneys submitted to 30 minutes of warm ischemia.

Cryoablation of small kidney tumors

INTRODUCTION

Cryoablation (CA) has been broadly used mostly in the treatment of small renal masses (SRMs). The present review aims to define the current role of CA in the treatment of SRMs by assessing clinical indications and outcomes.

METHOD

A comprehensive review on patient selection, procedural details, perioperative complications, and short/long-term oncological and functional outcomes was conducted. For each section, a take-home message was formulated with level of evidence (LoE) according to Cochrane collaboration.

RESULTS

Age and comorbidity drive the choice of ablation in SRMs, although hospital setting also influences the decision. Technically in adequate CA or first post-CA control occurs in 3-5% of laparoscopic cryoablation (LCA) or percutaneous cryoablation (PCA) series. Meta-analysis does not evidence differences in the rate of residual tumor per person-year between the approaches (0.033 LCA vs. 0.046 PCA, p = 0.25). Perioperative complications (8-25%) are erratically reported. LCA has significantly lower likelihood of complications than minimally invasive partial nephrectomy (MIPN). Systematic reviews indicate 30-month local tumor progression rate of 8.5% for LCA in renal cell carcinoma but low metastatic progression (1-4.4%). Few LCA long-term follow-up series (mean/media 48-98 months) report recurrence-free survival (RFS) and cancer-specific survival (CSS) ranges of 80-100%. For PCA, Kaplan-Meier local disease-free survival (DFS) of 95.6% at 3-5 years [32] and 5-year overall survival and local RFS of 86.3% were reported. The decrease in renal function after CA is minimal, and the only risk factor associated is the basal estimated glomerular filtration rate (eGFR).

CONCLUSION

LoE 3a/b confirms lower CA perioperative complication rate and higher local progression rate than those for MIPN. CA preserves postoperative renal functional, without any evidence of differences in mid-/long-term follow-up compared to nephron sparing surgery.

Diagnostic accuracy of pre-operative imaging findings in presumed clinical T1a renal cell carcinomas

Despite the development of recent imaging modalities, certain pathological misdiagnoses remain for surgical specimens of presumed small renal cell carcinomas (RCCs). In the present study, a retrospective analysis of benign pathological lesions diagnosed as small RCC prior to surgery was performed. In total, the cases of 196 sporadic renal tumors that was surgically treated as clinical T1a RCCs were reviewed, and the accuracy of the pathological diagnoses was calculated. The pre-operative findings for benign pathological lesions was investigated, and the lesions were observed in 13 (6.63%) of the 196 tumors. Pre-operative computed tomography images were obtained in all cases, and magnetic resonance images were available in 10 cases. The diagnostic accuracy of imaging modalities was significantly lower in the tumors with a diameter of ≤20 mm. In all cases, the possible pathological diagnosis of RCC could not be excluded even by retrospective imaging analysis. Several benign pathological lesions were found in small renal masses presumed to be clinical T1a RCC. In conclusion, there may be limitations to the pre-operative imaging for certain types of small renal mass.

Robot-assisted partial nephrectomy in 95 consecutive patients: Oncological and functional outcomes at 3 years of follow-up

BACKGROUND

We present the oncological and functional results from a series of 43 patients with renal tumours, treated consecutively with robot-assisted partial nephrectomy (RPN).

MATERIALS AND METHOD

Between 2010 and 2014, we performed 95 RPNs. To assess the results, we included only those patients (n=43) who had a minimum follow-up of 2 years. A descriptive analysis was conducted of the demographic characteristics and perioperative variables. We employed Kaplan-Meier curves to assess overall survival, cancer-specific survival and recurrence-free survival.

RESULTS

The patients' mean age was 53.1±13.5 years. The mean preoperative tumour size was 3.7±2.3cm. The mean surgical time was 102.2±37.1min. The mean ischemia time was 21.27±7.74minutes, with a median intraoperative bleeding volume of 150mL (IQR, 87.5-425). There was a 7% rate of postoperative complications (Clavien≥III). There was no mortality. The average Fürhman grade was 2.5±0.56. There were no positive surgical margins or local recurrences. The median follow-up was 38±8 months, with an overal survival, recurrence-free survival and cancer-specific survival of 100% at 3 years of follow-up. The recurrence-free survival was 92,3% at 48 months of follow-up. The mean preoperative glomerular filtration rate was 91.04±28.17mL/min/1.73m(2), and the postoperative rate was 89.9±27.69mL/min/1.73m(2), with a nonsignificant reduction (P=.74).

CONCLUSIONS

The functional and oncological results of our series confirm the safety and efficacy of RPN. RPN offers optimal preservation of renal function and oncological control in the medium term.

Percutaneous image-guided cryoablation of small renal masses

Renal cell carcinoma is a common malignancy with increasing incidence due to the incidental detection of non-symptomatic small renal masses on imaging. Management of these small tumors has evolved toward minimally invasive nephron-sparing techniques which include partial nephrectomy and image-guided ablation. Cryoablation and radiofrequency ablation are the most utilized ablation modalities with the former more suited for larger and central renal masses due to intra-procedural visualization of the ablation zone and reduced pelvicalyceal injury. In this article, we review the epidemiology and natural history of renal cell carcinoma, the role of biopsy, and the management options available-surgery, image-guided ablation, and active surveillance-with a focus on cryoablation. The clinical outcomes of the longer term maturing cryoablation data are discussed with reference to partial nephrectomy and radiofrequency ablation. Image-guided ablation has often been the management choice in patients deemed unfit for surgery; however, growing evidence from published series demonstrates image-guided ablation as a sound alternative treatment with equivalent oncological outcomes and minimal patient impact.

Urologische Malignome und rheumatoide Arthritis

Urologische Malignome sind relativ häufig und nehmen mit zunehmendem Lebensalter zu. Der demografische Wandel führt dazu, dass bei immer mehr Patienten mit entzündlich-rheumatischen Erkrankungen urogenitale Tumoren koinzident sind oder unter antirheumatischer Therapie auftreten. Die Basistherapie rheumatischer Erkrankungen muss in dieses Fällen individuell sorgfältig abgewogen werden, obwohl die begrenzte Evidenz für die meisten Situationen gegen eine massive Risikoerhöhung durch konventionelle und/oder biologische Basistherapeutika spricht. Paraneoplastische Phänomene auch im Bewegungsapparat können durch urogenitale Malignome ausgelöst werden. Mit den sich abzeichnenden Umwälzungen der medikamentösen Tumortherapie durch die Immunonkologie ergeben sich darüber hinaus neue Herausforderungen für die interdisziplinäre Kooperation von Uroonkologen und Rheumatologen. In dieser Übersichtsarbeit werden unter Berücksichtigung der aktuellen deutschen und europäischen Leitlinien die Diagnostik, Standardbehandlung und Nachsorge urologischer Malignome skizziert. Wir beschreiben Kernaspekte, die von Urologen und Rheumatologen beachtet werden sollten. Durch persönliche Absprache, regelmäßigen Erfahrungsaustausch und Einbeziehung von Rheumatologen in interdisziplinäre Tumorboards sollte zukünftig eine bessere Behandlung unserer gemeinsamen Patienten möglich werden.

Percutaneous Needle Based Optical Coherence Tomography for the Differentiation of Renal Masses: a Pilot Cohort

PURPOSE

We determine the ability of percutaneous needle based optical coherence tomography to differentiate renal masses by using the attenuation coefficient (μOCT, mm(-1)) as a quantitative measure.

MATERIALS AND METHODS

Percutaneous needle based optical coherence tomography of the kidney was performed in patients presenting with a solid renal mass. A pathology specimen was acquired in the form of biopsies and/or a resection specimen. Optical coherence tomography results of 40 patients were correlated to pathology results of the resected specimens in order to derive μOCT values corresponding with oncocytoma and renal cell carcinoma, and with the 3 main subgroups of renal cell carcinoma. The sensitivity and specificity of optical coherence tomography in differentiating between oncocytoma and renal cell carcinoma were assessed through ROC analysis.

RESULTS

The median μOCT of oncocytoma (3.38 mm(-1)) was significantly lower (p=0.043) than the median μOCT of renal cell carcinoma (4.37 mm(-1)). ROC analysis showed a μOCT cutoff value of greater than 3.8 mm(-1) to yield a sensitivity, specificity, positive predictive value and negative predictive value of 86%, 75%, 97% and 37%, respectively, to differentiate between oncocytoma and renal cell carcinoma. The area under the ROC curve was 0.81. Median μOCT was significantly lower for oncocytoma vs clear cell renal cell carcinoma (3.38 vs 4.36 mm(-1), p=0.049) and for oncocytoma vs papillary renal cell carcinoma (3.38 vs 4.79 mm(-1), p=0.027).

CONCLUSIONS

We demonstrated that the μOCT is significantly higher in renal cell carcinoma vs oncocytoma, with ROC analysis showing promising results for their differentiation. This demonstrates the potential of percutaneous needle based optical coherence tomography to help in the differentiation of renal masses, thus warranting ongoing research.

Prediction of renal mass aggressiveness using clinical and radiographic features: a global, multicentre prospective study

OBJECTIVE

To examine the ability of preoperative clinical characteristics to predict histological features of renal masses (RMs).

PATIENTS AND METHODS

Data from consecutive patients with clinical stage I RMs treated surgically between 2010 and 2011 in the Clinical Research Office of Endourology Society (CROES) Renal Mass Registry were collected. Based on surgical histology, tumours were categorised as benign, low- or high-aggressiveness cancer. Multivariate logistic regression was used to estimate the probability of the histological group by clinical and radiographic features in the entire cohort and a subcohort of cT1a tumours. The performance of the models was studied by calibration, Nagelkerke's R(2) , and discrimination (area under the receiver operating characteristic curve).

RESULTS

The study cohort included 2 224 patients with a clinical stage I RM, of which 1 367 (61%) were cT1a. Benign lesions were found in 369 (16.6%), low-aggressiveness tumours in 1 156 (52%) and high-aggressiveness tumours in 699 (31.4%). Male gender, smoking history, increased tumour size, and lower exophytic rate were associated with malignancy and high-aggressiveness features (all P < 0.05). Models developed based on these characteristics had the ability to discriminate benign from malignant (bootstrap corrected c-index of 0.64) and high-aggressiveness tumours from benign and low-aggressiveness tumours (bootstrap corrected c-index of 0.66). Similar results were achieved in the cT1a subgroup. The c-index of tumour diameter as a single predictor of malignancy and high-aggressiveness tumours in the entire cohort was 0.6 and 0.63, respectively.

CONCLUSION

Although older age, male gender, smoking history, increased tumour diameter, and reduced exophytic rate are associated with malignancy and high aggressiveness of clinical stage I RMs, models incorporating these characteristics have modest discriminating power, being only slightly better than the predictive ability of tumour size alone.

Multidisciplinary management of clear-cell renal cell carcinoma in Africa and the Middle East: current practice and recommendations for improvement

The management of renal cell carcinoma (RCC) has evolved considerably in recent years. This report represents the consensus of 22 relevant medical specialists from Africa and the Middle East region engaged in the management of RCC. Partial or radical nephrectomy is the standard of care for most patients with localized RCC. It is essential that patients are followed up appropriately after surgery to enable local and distant relapses to be identified and treated promptly. The treatment of advanced/metastatic disease has changed dramatically with the introduction of targeted therapies. Follow-up of these patients enables therapy optimization and assessment of response to treatment. There was universal agreement on the importance of management of RCC by a multidisciplinary team supported by a multidisciplinary tumor board. Barriers hindering this approach were identified. These included lack of awareness of the benefits of multidisciplinary team role, poor communication among relevant disciplines, time constraints, and specifics of private practice. Other challenges include shortage of expert specialists as urologists and oncologists and lack of local management guidelines in some countries. Solutions were proposed and discussed. Medical educational initiatives and awareness activities were highlighted as keys to encouraging cooperation between specialties to improve patients’ outcome. Establishing combined genitourinary cancer clinics and formal referral systems should encourage a culture of effective communication. Joining forces with professionals in peripheral areas and the private sector is likely to help standardize care. Sustained action will be required to ensure that all patients with RCC in the region benefit from up-to-date care.