Are urologists and radiologists equally effective in determining the RENAL Nephrometry score?

BACKGROUND: The RENAL nephrometry score (RNS) allows description of the anatomy and the complexity of renal masses. This study aimed to investigate the interobserver reproducibility of the RNS between a radiologist and a urologist. METHODS: The computed tomography (CT) scans of patients undergoing partial nephrectomy in the authors' department between June 2010 and June 2013 were analyzed for determination of the RNS by a urologist and a radiologist blinded to the medical records. Cohen's kappa coefficient was used for interobserver reproducibility assessment. Correlations with per- and postoperative complication rates and renal function were assessed. RESULTS: The study included 52 consecutive patients with a mean age of 55 years. The average score was 7.4 ± 1.7 for the urologist and 7.3 ± 1.5 for the radiologist. The Cohen's kappa was 0.81 for R, 0.47 for E, 0.63 for N, 0.28 for A, and 0.21 for L. The Pearson's coefficient for the total RNS was 0.70. The operative time and the occurrence of major complications were significantly correlated with the complexity assessed by the score of both observers. In the univariate analysis, the RNS, the American Society of Anesthesiologists score, and the patient's age were significantly associated with major complication rates. In the multivariate analysis, the RNS remained significantly associated with major complications. No significant difference in postoperative renal function according to complexity group was found by either the urologist or the radiologist. CONCLUSIONS: The reproducibility of the RNS between the radiologist and the urologist was not very good, especially for some items referring to the location of the tumor, although the major complication rates were significantly associated with the RNS for both observers.

Nephron-sparing surgery is superior to radical nephrectomy in preserving renal function benefit even when expanding indications beyond the traditional 4-cm cutoff.

OBJECTIVES: To analyze to what extent partial nephrectomy (PN) is superior to radical nephrectomy (RN) in preserving renal function outcome in relation to tumor size indication. METHODS AND MATERIALS: Clinical data from 973 patients operated at 9 academic institutions were retrospectively analyzed. Glomerular filtration rate (GFR) before and after surgery was calculated with the abbreviated Modification of the Diet in Renal Disease equation. For a fair comparison between the 2 techniques, all imperative indications for PN were excluded. A shift to a less favorable GFR group following surgery was considered clinically significant. RESULTS: Median age at diagnosis was 60 years (19-91). Tumor size was smaller than 4 cm in 665 (68.3%) cases and larger than 4 cm in 308 (31.7%) cases. PN and RN were performed in 663 (68.1%) and 310 (31.9%) patients, respectively. In univariate analysis, patients undergoing PN had a smaller risk for developing significant GFR change following surgery than those undergoing RN did. This was true for tumors≤4 cm (P = 0.0001) and for tumors>4 cm (P = 0.0001). In multivariate analysis, the following criteria were independent predictive factors for developing significant postoperative GFR loss: the use of RN (P = 0.0001), preoperative GFR<60 ml/min (P = 0.0001), tumor size≥4 cm (P = 0.0001), and older age at diagnosis (P = 0.0001). CONCLUSIONS: The renal function benefit carried out by elective PN over RN persists even when expanding nephron-sparing surgery indications beyond the traditional 4-cm cutoff.