Comparison of RENAL, PADUA, and C-index scoring systems in predicting perioperative outcomes after nephron sparing surgery

Abstract

Introduction and Objective: The RENAL, PADUA and centrality index (C-index) nephrometry scoring systems (SS) have been individually evaluated for their role in predicting trifecta outcomes after nephron-sparing surgery (NSS). However, there is little data on their comparative superiority. The present study was designed to evaluate the predictive value of three SS and to assess interobserver reliability. Materials and Methods: Fifty patients undergoing NSS at our center between January 2014 and April 2016 were included in the study. The demographic details were noted. Images (computed tomography [CT] scans or magnetic resonance imaging) were reviewed by a urologist and a radiologist independently and RENAL, PADUA, and C-index were calculated. The correlation between these scoring system and trifecta outcomes were calculated. Results: The RENAL and PADUA score did not correlate with any of the perioperative parameters. However, C-index had a significant correlation with operative time (OT) (P = 0.02) and trifecta outcomes (P < 0.05). There was an excellent concordance between the two observers in scoring the RENAL score (α = 0.915; intraclass correlation coefficient [ICC] = 0.814) and PADUA score (α = 0.816; ICC = 0.689 [P < 0.001]). There was lesser although acceptable concordance in the calculation of C-index (ICC −0.552; α −0.711). Conclusions: There is good correlation among all the 3 SS. C-index has lower reproducibility due to difficult mathematical calculation but correlated best with trifecta outcomes.