Diagnostic accuracy of retrospective application of the Vesical Imaging-Reporting and Data System: preliminary results

OBJECTIVE: To evaluate the retrospective accuracy of the Vesical Imaging-Reporting and Data System (VI-RADS) in detecting muscle invasion in bladder cancer. MATERIALS AND METHODS: We investigated patients who underwent pelvic magnetic resonance imaging and were submitted to transurethral resection of a bladder tumor between 2015 and 2018. Thirty cases were reviewed by radiologists blinded to the final clinical stage. The VI-RADS score was applied and compared with the histopathological findings in the surgical specimen. RESULTS: Of the 30 patients with suspicious bladder lesions, 5 (16.6%) had benign histopathological findings, 17 (56.6%) had non-muscle-invasive bladder cancer, and 8 (26.6%) had muscle-invasive bladder cancer. The optimal criterion to detect muscle-invasive bladder cancer was a final VI-RADS score > 3, for which the sensitivity and specificity were 100% (95% CI: 56.0-100%) and 90.9% (95% CI: 69.3-98.4%), respectively. CONCLUSION: The VI-RADS appears to estimate correctly the degree of muscle invasion in suspicious bladder lesions. However, prospective studies evaluating larger samples are needed in order to validate the method.