RESUMO
PURPOSE: Our study is designed to examine the diagnostic performance of diffusion-weighted magnetic resonance imaging (DW-MRI) for bladder cancers (BC), and to determine whether DW-MRI can differentiate muscle invasive bladder cancer (MIBC) from non-MIBC (NMIBC). METHODS: A meta-analysis was performed of published studies that investigated the performance of DW-MRI for BC. These studies were retrieved from scientific literature databases using sensitive electronic search strategies. The STATA 12.0 and Meta-disc software were employed for statistical analyses of data extracted from selected studies. RESULTS: Our search initially returned 230 articles, of which 11 met the inclusion criteria and were enrolled into the final meta-analysis. Five of the included studies reported the diagnostic performance of DW-MRI for BC with a cumulative total of 243 BC patients and 82 healthy subjects. Eight studies investigated the diagnostic performance of DW-MRI for differentiating MIBC from NMIBC, involving 259 MIBC lesions and 515 NMIBC lesions. Meta-analysis results were as follows: the diagnostic performance of DW-MRI for BC (sensitivity: 0.95 [0.75-0.99]; specificity: 0.85 [0.74-0.92]; positive likelihood ratio: 6.45 [3.64-11.42]; negative likelihood ratio: 0.055 [0.009-0.333]; diagnostic odds ratio: 117.11 [19.37-708.05]; area under the curve (AUC): 0.91); the diagnostic performance of DW-MRI to differentiate MIBC from NMIBC (sensitivity: 0.85 [0.76 - 0.91]; specificity: 0.90 [0.87 - 0.93]; positive likelihood ratio:8.81[6.43 - 12.07]; negative likelihood ratio: 0.16 [0.10 - 0.28]; diagnostic odds ratio: 53.95 [25.68 - 113.33]; AUC: 0.92). CONCLUSION: DW-MRI has an outstanding diagnostic performance, with advanced sensitivity and specificity, for imaging of bladder cancers and for differentiating MIBC from NMIBC.