ORIGINAL ARTICLE   Free access

Minerva Urologica e Nefrologica 2019 June;71(3):249-57

DOI: 10.23736/S0393-2249.18.03134-X

Copyright © 2018 EDIZIONI MINERVA MEDICA

language: English

Improved prediction of nephron-sparing surgery versus radical nephrectomy by the optimized R.E.N.A.L. Score in patients undergoing surgery for renal masses

Alexander STERZIK ¹, Olga SOLYANIK ¹, Christian EICHELBERG ², Marion JOST ², Anno GRASER ¹, Eva-Maria LAUSENMEYER ², Wolfgang OTTO ², Raphaela WAIDELICH ³, Christian G. STIEF ³, Maximilian BURGER ², Matthias MAY ⁴ ✉, Sabine D. BROOKMAN-MAY ³

¹ Department of Radiology, Ludwig-Maximilians-University, Munich, Germany; ² Department of Urology, Caritas-Hospital St. Josef, University of Regensburg, Regensburg, Germany; ³ Department of Urology, Ludwig-Maximilians-University, Munich, Germany; ⁴ Department of Urology, St. Elisabeth-Hospital Straubing, Straubing, Germany

BACKGROUND: One major objective of currently available morphometric scores (MS) for renal masses, i.e., R.E.N.A.L., PADUA classification, Centrality-Index, is the prediction of type of surgery (nephron-sparin surgery [NSS] or radical nephrectomy [RN]).
METHODS: Based on a prospective study protocol, various MS were assigned and calculated for 108 patients undergoing surgical treatment for renal masses at a single academic center. MS calculation was based on preoperative computed-tomography or magnet-resonance-imaging and performed by two independent readers blinded for surgical approach and outcome. Multivariable logistic-regression- and ROC-analyses were performed to assess the predictive value of various MS for surgical approach and the correlation of clinical parameters with nephrectomy type. Furthermore, the association with perioperative outcome parameters was evaluated.
RESULTS: None of the tested MS was significantly superior to tumor size alone (area under the curve [AUC]=0.82) in predicting RN, with Centrality-Index showing the best association (AUC=0.88). Based on these findings, a simplified and optimized R.E.N.A.L. Score (optR.E.N.A.L.) was developed with different weightings of included parameters, which did not only show a significantly enhanced association with surgery type (AUC=0.93) than tumor size, but also outperformed all 1st and 2nd generation MS tested in the study cohort. Besides a modest correlation with postoperative change in renal function, no association with perioperative outcome variables was found for all MS including optR.E.N.A.L.
CONCLUSIONS: optR.E.N.A.L. represents a promising improvement of the preexisting R.E.N.A.L. Score with higher predictive ability for nephrectomy type than established MS and may serve as a benchmarking tool for nephrectomy assessment and comparison of surgical strategies.

KEY WORDS: Kidney neoplasms; Nephrectomy; Complications; Tumor burden