Could Bladder Multiparametric MRI Be Introduced in Routine Clinical Practice? Role of the New VI-RADS Score: Results From a Prospective Study.

Abstract

The Vesical Imaging Reporting and Data System (VI-RADS) was recently introduced as a standardized approach to reporting multiparametric magnetic resonance imaging (mpMRI) for bladder cancer. We aimed to prospectively analyze its routine use and its diagnostic performance in discriminating non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). A total of 38 patients with diagnosis of suspect bladder cancer at cystoscopy underwent bladder mpMRI before transurethral resection of the bladder (TURB). Bladder tumors were categorized according to the VI-RADS. After TURB, the VI-RADS score was compared with histological report for each lesion separately. Receiving operating characteristic and decision curve analyses were used to assess its accuracy and clinical utility. A total of 68 lesions were included, of which 7 (10.3%) were MIBC. The pooled accuracy was 90.0% (95% confidence interval [CI], 75.4%-98.7%). The best threshold was estimated as VI-RADS 4, showing a sensitivity of 85.7% (95% CI, 57.1%-100%) and a specificity of 86.9% (95% CI, 78.7%-95.1%). Decision curve analyses showed that using VI-RADS≥4 improved the net benefit compared with any default strategy for threshold probabilities of MIBCup to ∼40%, which is a reasonable clinical threshold for planning further treatments. Our prospective study shows that the use of VI-RADS as a standardized reporting method is appealing and could be considered in clinical practice owing to its high accuracy.