title: Usefulness of MDCT to Differentiate Between Renal Cell Carcinoma and Oncocytoma: Development of a Predictive Model.
abstract: OBJECTIVE
  The objective of our study was to identify the most useful parameters to differentiate between renal cell carcinoma (RCC) and oncocytoma using four-phase CT.
  
  
  METHODS
  Ninety-seven patients with solid renal lesions who underwent surgery with four-phase preoperative CT evaluation and with pathologic diagnosis of RCC or oncocytoma were included in the study. Features of tumors and the enhancement pattern in the four CT phases were evaluated and analyzed. Logistic regression models were used to assess independent predictors for malignancy.
  
  
  RESULTS
  Histopathologically, 13 tumors were oncocytomas and 84 were RCCs. RCCs were larger (6.20 cm vs 3.21 cm, p = 0.0004) and more often enhanced heterogeneously (66 vs 6, p = 0.02). Lesions that were larger than 4 cm showed a significantly higher risk of malignancy (p = 0.0046). Significant differences were found in intensity of nodule enhancement between the nephrographic and the excretory phases with respect to the unenhanced phase (p = 0.003 and p = 0.0026). At multivariate analysis, parameters that were independent predictors of malignancy were enhancement pattern, with RCCs more often having heterogeneous enhancement than oncocytomas (odds ratio [OR], 0.18; 95% CI, 0.04-0.90), and nodule enhancement in the excretory phase in relation to the unenhanced phase, with RCCs showing lower enhancement (OR, 0.93; 95% CI, 0.88-0.97), and a size larger than 4 cm (OR, 4.01; 95% CI, 0.70-23.14).
  
  
  CONCLUSIONS
  The combination of different CT parameters including lesion size larger than 4 cm, lesion enhancement in the excretory phase in relation to the unenhanced phase, and heterogeneous enhancement pattern helps distinguish RCC from oncocytoma.
authors.affiliation: 1 Department of Radiology, CDIC, Hospital Clínic de Barcelona, Villarroel 170, Barcelona 08036, Spain.
authors.forename: Blanca
authors.initials: B
authors.lastname: Paño
authors.affiliation: 1 Department of Radiology, CDIC, Hospital Clínic de Barcelona, Villarroel 170, Barcelona 08036, Spain.
authors.forename: Napoleon
authors.initials: N
authors.lastname: Macías
authors.affiliation: 1 Department of Radiology, CDIC, Hospital Clínic de Barcelona, Villarroel 170, Barcelona 08036, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Salvador
authors.affiliation: 1 Department of Radiology, CDIC, Hospital Clínic de Barcelona, Villarroel 170, Barcelona 08036, Spain.|2 Department of Biostatistics and Data Management Core Facility, IDIBAPS, Hospital Clinic de Barcelona, Barcelona, Spain.
authors.forename: Ferran
authors.initials: F
authors.lastname: Torres
authors.affiliation: 1 Department of Radiology, CDIC, Hospital Clínic de Barcelona, Villarroel 170, Barcelona 08036, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Buñesch
authors.affiliation: 1 Department of Radiology, CDIC, Hospital Clínic de Barcelona, Villarroel 170, Barcelona 08036, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Sebastià
authors.affiliation: 1 Department of Radiology, CDIC, Hospital Clínic de Barcelona, Villarroel 170, Barcelona 08036, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Nicolau
mesh_terms: D018249:Adenoma, Oxyphilic / Q000000981:diagnostic imaging*; D000368:Aged; D000465:Algorithms; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D003974:Diatrizoate Meglumine; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D012189:Retrospective Studies; D012984:Software
chemical_list: D003287:Contrast Media; D003974:Diatrizoate Meglumine; D007472:Iohexol; C038192:iopromide
keywords: MDCT; oncocytoma; renal cell carcinoma