Utility of the R.E.N.A.L. Nephrometry Scoring System in Objectifying Treatment Decision-making of the Enhancing Renal Mass

OBJECTIVE To evaluate the treatment patterns of solid renal masses according to the quantifiable anatomic features using nephrometry. The treatment of localized renal cell carcinoma remains overly subjective. The R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to the collecting system or sinus in millimeters, anterior/posterior, location relative to polar lines) nephrometry score quantifies the salient characteristics of renal mass anatomy in an objective and reproducible manner. METHODS Nephrometry scores were available in 615 patients in our prospective kidney tumor database (2000-2010). The nephrometry score sum and its individual component scores were analyzed to determine their relationship to treatment approach. RESULTS The median age, age-adjusted Charlson co-morbidity index, and estimated glomerular filtration rate was 60 years (range 25-89), 2 (range 0-10), and 80.5 mL/min (range 5.1-120.0), respectively. Increasing tumor complexity, as measured by a greater overall nephrometry score was associated with both radical nephrectomy and open partial nephrectomy (P < .0001). Compared with patients who underwent partial nephrectomy, the patients treated with radical nephrectomy had a significantly greater size (R), central proximity (N), and location (L) component scores (P < .001). Furthermore, tumors treated with radical nephrectomy were more often hilar (P < .001). Similarly, compared with minimally invasive partial nephrectomy (laparoscopic or robotic), open partial nephrectomy was associated with an increasing individual component score for size, endophytic, and central proximity to the collecting system (P < .001) and nonpolar location (P = .016). CONCLUSION The R. E. N. A. L nephrometry score standardizes the reporting of solid renal masses and appears to effectively stratify by treatment type. Although only 1 part of the treatment decision-making process, nephrometry aids in objectifying previously subjective measures. UROLOGY 78: 1089-1094, 2011. (C) 2011 Elsevier Inc.