Associations between R.E.N.A.L. nephrometry score and survival outcomes in renal tumours.

OBJECTIVE: The radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score could be used to predict surgical outcomes and renal tumour aggressiveness. We aimed to analyse its associations with survival outcomes. METHODS: We included 1368 patients with sporadic, unilateral and non-metastatic renal tumours who received curative nephrectomy in Zhongshan Hospital from January 2009 to September 2019. Radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores were assigned by three urologists based on preoperative CT/MRI scans. Correlations between parameters or sum of radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores, overall survival and recurrence-free survival were analysed by Kaplan-Meier analyses and the multivariate Cox regression model. We further compared survival outcomes between patients who received partial nephrectomy and patients who received radical nephrectomy. RESULTS: We observed statistically significant associations between all components of radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores and oncologic outcomes, including R (radius) (overall survival, P < 0.001; recurrence-free survival , P < 0.001), E (exophytic/endophytic) (overall survival, P = 0.003; recurrence-free survival, P < 0.001), N (nearness) (overall survival, P = 0.063; recurrence-free survival, P < 0.001), A (anterior/posterior) (overall survival, P < 0.001; recurrence-free survival, P = 0.005), L (location) (overall survival, P = 0.008; recurrence-free survival, P < 0.001) and suffix 'h' (overall survival, P = 0.237; recurrence-free survival, P = 0.034). Kaplan-Meier curves of overall survival and recurrence-free survival rates were significantly different when stratified by radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score complexity group (overall survival, P < 0.001; recurrence-free survival, P < 0.001). After adjusting for tumour stage and grade, radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score as continuous variables was an adverse independent risk factor for survival outcomes [P = 0.027, hazard ratio (95% confidence interval) = 1.151 (1.016-1.303)] and recurrence-free survival [P < 0.001, hazard ratio (95% confidence interval) = 1.299 (1.125-1.501)]. For tumours with radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores of 4 and 5, partial nephrectomy showed a survival benefit than radical nephrectomy. CONCLUSION: Both components and complexity groups of the radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score are associated with survival outcomes in renal tumour patients.

Impact of tumor contact surface area on collecting system entry in robot-assisted partial nephrectomy: a retrospective analysis.

BACKGROUND: Collecting system entry in robot-assisted partial nephrectomy may occur even in cases showing a low N factor in the R.E.N.A.L nephrometry score. Therefore, in this study, we focused on the tumor contact surface area with the adjacent renal parenchyma and attempted to construct a novel predictive model for collecting system entry. METHODS: Among 190 patients who underwent robot-assisted partial nephrectomy at our institution from 2015 to 2021, 94 patients with a low N factor (1-2) were analyzed. Contact surface was measured with three-dimensional imaging software and defined as the C factor, classified as C1, < 10 cm [2]; C2, ≥ 10 and < 15 cm [2]; and C3: ≥ 15 cm [2]. Additionally, a modified R factor (mR) was classified as mR1, < 20 mm; mR2, ≥ 20 and < 40 mm; and mR3, ≥ 40 mm. We discussed the factors influencing collecting system entry, including the C factor, and created a novel collecting system entry predictive model. RESULTS: Collecting system entry was observed in 32 patients with a low N factor (34%). The C factor was the only independent predictive factor for collecting system entry in multivariate regression analysis (odds ratio: 4.195, 95% CI: 2.160-8.146, p < 0.0001). Models including the C factor showed better discriminative power than the models without the C factor. CONCLUSIONS: The new predictive model, including the C factor in N1-2 cases, may be beneficial, considering its indication for preoperative ureteral catheter placement in patients undergoing robot-assisted partial nephrectomy.

Pathological diagnostic nomograms for predicting malignant histology and unfavorable pathology in patients with endophytic renal tumor.

Purpose: To develop and validate nomograms for pre-treatment prediction of malignant histology (MH) and unfavorable pathology (UP) in patients with endophytic renal tumors (ERTs). Methods: We retrospectively reviewed the clinical information of 3245 patients with ERTs accepted surgical treatment in our center. Eventually, 333 eligible patients were included and randomly enrolled into training and testing sets in a ratio of 7:3. We performed univariable and multivariable logistic regression analyses to determine the independent risk factors of MH and UP in the training set and developed the pathological diagnostic models of MH and UP. The optimal model was used to construct a nomogram for MH and UP. The area under the receiver operating characteristics (ROC) curves (AUC), calibration curves and decision curve analyses (DCA) were used to evaluate the predictive performance of models. Results: Overall, 172 patients with MH and 50 patients with UP were enrolled in the training set; and 74 patients with MH and 21 patients with UP were enrolled in the validation set. Sex, neutrophil-to-lymphocyte ratio (NLR), R score, N score and R.E.N.A.L. score were the independent predictors of MH; and BMI, NLR, tumor size and R score were the independent predictors of UP. Single-variable and multiple-variable models were constructed based on these independent predictors. Among these predictive models, the malignant histology-risk nomogram consisted of sex, NLR, R score and N score and the unfavorable pathology-risk nomogram consisted of BMI, NLR and R score performed an optimal predictive performance, which reflected in the highest AUC (0.842 and 0.808, respectively), the favorable calibration curves and the best clinical net benefit. In addition, if demographic characteristics and laboratory tests were excluded from the nomograms, only the components of the R.E.N.A.L. Nephrometry Score system were included to predict MH and UP, the AUC decreased to 0.781 and 0.660, respectively (P=0.001 and 0.013, respectively). Conclusion: In our study, the pathological diagnostic models for predicting malignant and aggressive histological features for patients with ERTs showed outstanding predictive performance and convenience. The use of the models can greatly assist urologists in individualizing the management of their patients.

Comparison of surgical outcomes and split renal function between laparoscopic and robot-assisted partial nephrectomy: a propensity score-matched analysis.

PURPOSE: The objective of this study was to compare perioperative outcomes and total and split renal function between laparoscopic partial nephrectomy (LPN) and robot-assisted partial nephrectomy (RAPN). Predictive risk factors of preservation of operated renal function were also assessed. METHODS: We retrospectively analyzed 173 patients who underwent LPN (n = 84) or RAPN (n = 89) between 2010 and 2020. After propensity score matching (1:1), perioperative outcomes and total and split renal function were assessed. Logistic regression analysis was used to evaluate predictive risk factors of preservation of operated renal function. Trifecta criteria were defined as negative surgical margins, warm ischemia time (WIT) < 25 min, and no complications more than Clavien-Dindo grade II within 4 weeks after surgery. Split renal function was evaluated by mercaptoacetyltriglycine renal scan. RESULTS: After propensity score matching, 42 patients were allocated to each group. RAPN was associated with significantly shorter WIT (RAPN vs LPN: 12 vs 22 min; p < 0.0001) and higher trifecta achievement rate (93.3 vs 64.2%; p < 0.0001). Other perioperative outcomes and total and split renal function were not significantly different between LPN and RAPN. The R.E.N.A.L. nephrometry score (RNS) was a predictive risk factor of preservation of operated renal function in the multivariable logistic regression analysis (odds ratio 1.68, 95% confidence interval 1.29-2.20, p < 0.0001). CONCLUSIONS: RAPN improved WIT and trifecta achievement rate, but it did not improve the preservation of operated renal function, for which RNS was found to be a strong predictive risk factor.

Comparison of Perioperative Outcomes Between Laparoscopic and Open Partial Nephrectomy for Different Complexity Renal Cell Carcinoma Based on the R.E.N.A.L. Nephrometry Score.

PURPOSE: This study aimed to compare perioperative outcomes of open partial nephrectomy (OPN) and laparoscopic partial nephrectomy (LPN) from a retrospective single-center dataset. PATIENTS AND METHODS: A retrospective single-center analysis of 210 patients who underwent open (n=91) or laparoscopic (n =119) partial nephrectomy for RCC was conducted between 2012 and 2015. All patients were grouped into low complexity, moderate complexity, and high complexity according to the R.E.N.A.L. Nephrometry Score, respectively. The rates of intraoperative and postoperative complications estimated blood loss, warm ischemia time, operative time, conversion of laparoscopic procedure to open surgery, and postoperative length of stay were assessed for both procedures. RESULTS: In low complexity group (n=93), patients undergoing LPN (n=52) under ischemia conditions had significantly longer renal artery clamp time (p < 0.001) and operative time (p = 0.001) compared with OPN (n=41). However, patients undergoing LPN had a significantly less postoperative length of stay (p=0.005) and estimated blood loss (p < 0.001) compared with OPN. There was no statistically significant difference in the rates of complications between LPN and OPN. In the moderate complexity group (n=114), 67 and 47 patients underwent LPN and OPN, respectively. LPN had notably longer warm ischemia time (p < 0.001) and operative time (p < 0.001) compared with OPN. There were no statistically significant differences in the rates of complications, estimated blood loss, and postoperative length of stay between LPN and OPN. In the high complexity group (n=3), all patients underwent OPN. CONCLUSION: OPN and LPN procedures performed in patients with low and moderate complexity tumors based on the RENAL Nephrometry score offer acceptable and comparable results. When applied to low complexity tumors, our data suggest that laparoscopic NSS is an effective, minimally invasive therapeutic approach with the advantages of less blood loss, earlier hospital discharge, and more rapid convalescence.

Interobserver Reliability of the RENAL Nephrometry Scoring System: Experience From a Developing Nation.

Introduction The RENAL (radius, exophytic/endophytic properties, nearness of tumor to the collecting system or sinus in millimeters, anterior/posterior, location relative to polar lines) nephrometry score (RENAL-NS) has been described as a structured and quantifiable method to describe a renal tumor's relevant anatomic features as they relate to the complexity of the lesion. We aim to evaluate a tumor's RENAL-NS and to assess the reproducibility of the score among different observers. Methods This retrospective study included 49 patients diagnosed with renal cell carcinoma (RCC) who had complete computed tomography (CT) data, RENAL-NS, and histopathology results. All patients underwent renal surgery/intervention at our center between January 2008 and December 2018. The radius of the lesion, exophytic/endophytic properties, nearness to the collecting system, anterior or posterior description, and location relative to the polar lines was used to calculate the score. Tumor complexity was graded as low, intermediate, or high. Two body imaging radiologists evaluated the data independently. Results Interobserver agreement for each of the RENAL-NS parameters, respectively, and overall complexity was calculated. The total agreement was 82%, 51%, 84%, 69%, 73%, and 90%, corresponding to Kappa values of 0.72, 0.33, 0.44, 0.49, 0.58, and 0.83, respectively. The radius, nearness to the collecting system, and total complexity showed the best agreement. Exophytic properties of the lesion showed the least agreement. For cases that were discordant in terms of the final score, no major implications in surgical planning were observed. Conclusion The results of this study show that the RENAL-NS is a useful tool to assess the anatomical features of renal tumors and it is easily reproducible, even for less experienced radiologists in a developing nation.

Association among the R.E.N.A.L. nephrometry score and clinical outcomes in patients with small renal masses treated with percutaneous contrast enhanced ultrasound radiofrequency ablation.

INTRODUCTION: An association between the R.E.N.A.L. nephrometry score (RNS) and clinical outcomes in patients with a small renal mass (SRM) has been proposed. We analyzed clinical outcomes according to the RNS in patients with a SRM treated with percutaneous contrast enhanced ultrasound (CEUS) radiofrequency ablation (RFA). MATERIAL AND METHODS: Patients with a SRM, who underwent RFA between January 2005 and March 2015, were retrospectively identified. The association between RNS and clinical outcomes was evaluated using parametric and non-parametric analysis. RESULTS: We analyzed 163 SRMs in 149 consecutive patients. The mean age was 71.7 years. Mean follow-up time was 33.3 months ±20.6 (2-102). The mean RNS was 5.6 ±1.52 (4-11). A total of 121 (74.2%) cases were of low complexity and 42 (25.8%) were medium complexity. We identified 11 cases of tumor persistence (6.7%). The mean RNS was 5.58 in the cases with no persistence and 5.73 in the cases with persistence (p = 0.788). We identified 15 (9.2%) cases of recurrence. The mean RNS was 5.57 ±0.1 (4-11) in the cases without recurrence and 5.73 ±0.4 (4-9) in recurrence cases (p = 0.804). Of the 76 biopsy proven RCC cases, 8 (10.5%) cases of recurrence were observed, 5 in the low complexity group and 3 in the medium complexity group (p = 0.690). A total of 9 (5.5%) cases of complications were observed, with 5 (4.3%) in the low complexity group and 4 cases in the medium complexity group (p = 0.23). The mean length of stay was 1.5 days with a significant difference between low and medium complexity groups (1.3 vs. 2.1 days, p = 0.02). The mean difference between preoperative eGFR and estimated eGFRat 12 months was -3.08 mL / min ±13.3 (-49.4-34.1) and was significant (p = 0.008).However, this variation did not show significant differences between the low and medium complexity groups (p = 0.936). All-cause mortality was 11.7%, 14 cases (11.6%) in the low complexity group and 5 (11.9%) in the medium complexity group (p = 1.0). No cases of renal cell carcinoma (RCC) specific mortality were identified. CONCLUSIONS: The RNS was not associated with tumor persistence, recurrence, cancer specific mortality, complications or renal function 12 months after the first treatment, showing significant difference only in length of hospital stay between low and medium complexity groups.

R.E.N.A.L. Nephrometry Score Predicts Non-neoplastic Parenchymal Volume Removed During Robotic Partial Nephrectomy.

OBJECTIVE: To assess the association between the R.E.N.A.L. Nephrometry score, the amount of non-neoplastic parenchymal volume (NNPV) removed, and the renal function decline in patients undergoing robotic partial nephrectomy (RPN). PATIENTS AND METHODS: The Multi-institutional Mount Sinai Kidney Cancer Database was used to identify 1235 patients who underwent RPN between January 2008 and February 2016, of whom 366 had complete data, including NNPV removed. Mann-Whitney U tests and univariable linear regression models were used to assess the relationships between R.E.N.A.L. Nephrometry score, warm ischemia time (WIT), and NNPV removed. Univariable and multivariable regression models were then used to assess the independent relationships of each of these variables with percent change in estimated glomerular filtration rates (eGFR) and acute kidney injury (AKI) within the first 30 postoperative days in addition to percent change in eGFR and progression to chronic kidney disease at a median follow-up of 6.9 months. RESULTS: Increasing R.E.N.A.L. Nephrometry score was shown to be a predictor of WIT (ß = 0.92, p < 0.001) and of NNPV removed (ß = 6.21, p < 0.001) in univariable analyses. In multivariable analysis, postoperative reduction in eGFR within the first 30 days of surgery was associated with both R.E.N.A.L. Nephrometry score (ß = -2.02, p < 0.001) and NNPV removed (ß = -5.19, p = 0.015). R.E.N.A.L. Nephrometry score (OR = 1.21, p = 0.013) and NNPV removed (OR = 1.90, p = 0.013) were also associated with an increased likelihood of AKI within the first 30 days. No significant association in this cohort was found between R.E.N.A.L. Nephrometry score, NNPV removed, or WIT and renal function decline at 6.9 months. CONCLUSION: The preoperative R.E.N.A.L. Nephrometry score can be used to predict postoperative pathologically determined healthy renal volume loss or NNPV removed. Removal of not just the tumor but also the healthy surrounding parenchyma is important in determining renal function decline. As our understanding of the importance of renal volume loss grows, NNPV removed gains increasing utility as an easily determinable postoperative variable.

Critical appraisal of first-generation renal tumor complexity scoring systems: Creation of a second-generation model of tumor complexity.

OBJECTIVE: To investigate whether a combination of variables from each nephrometry system improves performance. There are 3 first-generation systems that quantify tumor complexity: R.E.N.A.L. nephrometry score (RNS), preoperative aspects and dimensions used for an anatomical (PADUA) classification (PC), and centrality index (CI). Although each has been subjected to validation and comparative analysis, to our knowledge, no work has been done to combine variables from each method to optimize their performance. PATIENTS AND METHODS: Scores were assigned to each of 276 patients undergoing partial nephrectomy (PN) or radical nephrectomy (RN). Individual components of all 3 systems were evaluated in multivariable logistic regression analysis of surgery type (PN vs. RN) and combined into a "second-generation model." RESULTS: In multivariable analysis, each scoring system was a significant predictor of PN vs. RN (P<0.0001). Of the first-generation systems, CI was most highly correlated with surgery type (area under the curve [AUC] = 0.91), followed by RNS (AUC = 0.90) and PC (AUC = 0.88). Each individual component of these scoring systems was also a predictor of surgery type (P<0.0001). In a multivariable model incorporating each component individually, 4 were independent predictors of surgery type (each P<0.005): tumor size (RNS and PC), nearness to the collecting system (RNS), location along the lateral rim (PC), and centrality (CI). A novel model in which these 4 variables were rescaled outperformed each first-generation system (AUC = 0.91). CONCLUSIONS: Optimization of first-generation models of renal tumor complexity results in a novel scoring system, which strongly predicts surgery type. This second-generation model should aid comprehension, but future work is still needed to establish the most clinically useful model.

Application of modified R.E.N.A.L. nephrometry score system in evaluating the retroperitoneal partial nephrectomy for T1 renal cell carcinoma.

OBJECTIVE: This study aims to investigate the application of the modified R.E.N.A.L. nephrometry score system in evaluating the operation difficulty of retroperitoneal partial nephrectomy in T1 renal cell carcinoma patients. METHODS: A total of 52 patients with T1 renal cell carcinoma were enrolled. They all had retroperitoneal partial nephrectomy. Their clinical data was retrospectively analyzed. R.E.N.A.L. nephrometry score system was modified based on the features of retroperitoneal partial nephrectomy. The specificity, sensitivity and Youden index were compared between R.E.N.A.L. nephrometry score system and the modified R.E.N.A.L. nephrometry score system. The effect of the modified R.E.N.A.L. nephrometry score system on perioperative outcomes was analyzed. RESULTS: Three degrees of operation difficulty were defined by the modified R.E.N.A.L. nephrometry score system, which included the low, medium and high degree of operation difficulty. The specificity, sensitivity and Youden index of the modified R.E.N.A.L. nephrometry score system were better than those of the original R.E.N.A.L. nephrometry score system. Compared with low degree of operation difficulty, patients with medium and high degree of operation difficulty had significantly higher levels of operative time, warm ischemia time, and intraoperative blood loss (P < 0.05). And, the levels of operative time, warm ischemia time, and intraoperative blood loss in patients with high degree were significantly higher than those in patients with medium degree (P < 0.05). CONCLUSIONS: The modified R.E.N.A.L. nephrometry score system has a good effect in evaluating the operation difficulty of retroperitoneal partial nephrectomy.