title: Reproducibility and interobserver agreement of the R.E.N.A.L. nephrometry score: focus on imaging features.
abstract: OBJECTIVE
  To investigate the reproducibility and interobserver agreement for R.E.N.A.L. nephrometry scoring system.
  
  
  METHODS
  Two independent radiologists retrospectively analyzed 46 consecutive patients with renal masses, between 2008 and 2012, using the R.E.N.A.L. nephrometry score (RENAL-NS), which is based on the evaluation of five anatomical features of the tumor, as evaluated with computed tomography or magnetic resonance imaging:Radius,Exophytic/endophytic properties,Nearness to the collecting system,Anterior or posterior descriptor, andLocation relative to the polar line. Tumor complexity was graded as low, intermediate, or high. The interobserver agreement was calculated for the total score and for the score for each parameter. Surgical excision of the tumors was used as the standard of reference.
  
  
  RESULTS
  The interobserver agreement for each of the RENAL-NS parameters, respectively, a hilar location, and the total score was 98%, 80%, 100%, 89%, 85%, 89%, and 93% of patients, corresponding to kappa values of 0.96, 0.65, 1.00, 0.75, 0.72, 0.78, and 0.88, respectively. The Nearness, Radius, and total score showed the best agreement. For the cases that were discordant in terms of the final score, no major implications in surgical planning were observed.
  
  
  CONCLUSIONS
  The RENAL-NS is a structured, useful system to assess the anatomical features of renal tumors. It is easily applicable and reproducible, even for less experienced radiologists.
authors.affiliation: MD, Attending Radiologist, Radiology Department - Abdominal Imaging, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: Richard Mast
authors.initials: RM
authors.lastname: Vilaseca
authors.affiliation: MD, PhD, Associate Professor of Radiology, Radiology and Biomedical Engineering, University of California at San Francisco (UCSF), San Francisco, CA, USA.
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Westphalen
authors.affiliation: MD, Attending Radiologist, Internal Medicine Department - Imaging Division, Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil.
authors.forename: Henrique Ferreira
authors.initials: HF
authors.lastname: Reis
authors.affiliation: MD, Attending Radiologist, Internal Medicine Department - Imaging Division, Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil.
authors.forename: Orlando Salomão
authors.initials: OS
authors.lastname: Zogbi
authors.affiliation: MD, PhD, Assistant Professor, Department of Pathology, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil.
authors.forename: Gyl Eanes
authors.initials: GE
authors.lastname: Silva
authors.affiliation: MD, PhD, Assistant Professor, Department of Surgery - Urology Division, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil.
authors.forename: Rodolfo Borges
authors.initials: RB
authors.lastname: Dos Reis
authors.affiliation: MD, PhD, Associate Professor, Department of Radiology, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil.
authors.forename: Valdair Francisco
authors.initials: VF
authors.lastname: Muglia
keywords: Carcinoma, renal cell; Computed tomography; Kidney neoplasms; Magnetic resonance imaging; Neoplasm staging