title: DWI for Renal Mass Characterization: Systematic Review and Meta-Analysis of Diagnostic Test Performance.
abstract: OBJECTIVE
  The objective of our study was to perform a systematic review and meta-analysis of the test performance of DWI in the characterization of renal masses.
  
  
  METHODS
  We performed searches of three electronic databases for studies on renal mass characterization using DWI. Methodologic quality was assessed for each study. We quantitatively analyzed test performance for three clinical problems: first, benign versus malignant lesions; second, clear cell renal cell carcinoma (RCC) versus other malignancies; and, third, high-versus low-grade clear cell RCCs. We summarized performance as a single pair of sensitivity and specificity values or a summary ROC curve.
  
  
  RESULTS
  The studies in the literature were limited in both quantity and quality. For classification of benign versus malignant lesions, four studies with 279 lesions yielded a single summary estimate of 86% sensitivity and 78% specificity. For differentiation of clear cell RCC from other malignancies, five studies showed marked heterogeneity not conducive to meta-analysis. For differentiation of high-from low-grade clear cell RCCs, three studies with 110 lesions showed a threshold effect appropriate for summary ROC construction: The AUC was 0.83.
  
  
  CONCLUSIONS
  Evidence suggests moderate accuracy of DWI for the prediction of malignancy and high-grade clear cell cancers, whereas DWI performance for ascertaining clear cell histologic grade remains unclear. To develop DWI as a noninvasive approach for the evaluation of solid renal masses, prospective studies with standardized test parameters are needed to better establish DWI performance and its impact on patient outcomes.
authors.affiliation: 1 Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Ave, New York, NY 10016.|2 Department of Population Health, NYU School of Medicine, NYU Langone Medical Center, New York, NY.
authors.forename: Stella K
authors.initials: SK
authors.lastname: Kang
authors.affiliation: 3 Harvard University, Cambridge, MA.
authors.forename: Angela
authors.initials: A
authors.lastname: Zhang
authors.affiliation: 4 Institute for Technology Assessment, Massachusetts General Hospital, Boston, MA.|5 Department of Radiology, Massachusetts General Hospital, Boston, MA.
authors.forename: Pari V
authors.initials: PV
authors.lastname: Pandharipande
authors.affiliation: 1 Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Ave, New York, NY 10016.
authors.forename: Hersh
authors.initials: H
authors.lastname: Chandarana
authors.affiliation: 2 Department of Population Health, NYU School of Medicine, NYU Langone Medical Center, New York, NY.|6 Department of Medicine, NYU School of Medicine, NYU Langone Medical Center, New York, NY.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Braithwaite
authors.affiliation: 7 Department of Medicine, University of Vermont College of Medicine, Burlington, VT.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Littenberg
mesh_terms: D002292:Carcinoma, Renal Cell / Q000175:diagnosis* / Q000473:pathology; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000473:pathology; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media
keywords: DWI; diagnostic test accuracy; meta-analysis; renal mass; systematic review