EAU 2018: Comprehensive Comparison of CSA, RENAL, PADUA, and C-Index in Predicting Functional Change after Partial Nephrectomy in Small Renal Mass

Copenhagen, Denmark (UroToday.com) This study evaluated the renal cortical volume (RCV) change after nephron sparing surgery and the predictive value of nephrometry score in RCV preservation after partial nephrectomy (PN).

Overall, 162 patients with renal tumors treated with open PN were retrospectively analyzed. The RCV of tumor-bearing kidney was measured preoperatively and postoperatively using dedicated software. CSA, RENAL, PADUA, and C-index scores were obtained from preoperative CT scan. The correlation between nephrometry scores and perioperative parameters were evaluated, and the 4 nephrometry scores were compared in predicting reduction in RCV.

The median percent reduction in RCV of the operated kidney was 17% and the median percent reduction in global eGFR was 5.6%. All scores showed a significant association with reduction in RCV (p<0.001), percent reduction in RCV (p<0.001), and estimated blood loss (CSA and C-index, p<0.001; RENAL, p=0.017; PADUA, p=0.004). CSA and PADUA scores showed a significant association with percent reduction in eGFR (p=0.038 and p=0.026). On multivariable analysis CSA, PADUA, and C-index independently affected percent reduction in RCV (p=0.003, p=0.025, and p=0.013, respectively). No correlation was found for the RENAL score (p=0.234). On ROC curve analysis CSA was a better independent predictor of greater than 10% and 20% percent reduction in RCV (AUC 0.819 and 0.723, respectively).

In conclusion, CT based RCV measurement successfully differentiated the RCV change after PN. Compared to other nephrometry scores, CSA was shown to be a superior predictor for RCV change of the operated kidney.

Presented by:  Lee C.H, Inje University Busan Paik Hospital, Inje University College of Medicine, Dept. of Urology

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, twitter: @GoldbergHanan at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark