Real-world diagnostic performance of pre-TURBT multiparametric MRI using VI-RADS for detecting muscle-invasive bladder cancer: A retrospective single-center study

Introduction: VI-RADS (Vesical Imaging-Reporting and Data System) is a standardized scoring system developed to assess the likelihood of muscle-invasive bladder cancer (MIBC) using multiparametric magnetic resonance imaging (mpMRI). Our aim was to report our 3-year experience in using mpMRI to differentiate MIBC from non-muscle invasive bladder cancer (NMIBC). All radiological reports were generated using the VI-RADS score. Materials and methods: Patients with finding of ⩾15 mm suspicious bladder cancer at Ultrasound, CT scan or flexible cystoscopy underwent mpMRI before transurethral resection of bladder tumor (TURBT). We used a 5-point VI-RADS score, derived using T2-weighted MRI, diffusion-weighted imaging, and dynamic contrast enhancement. All examinations were performed on a 1.5 T scanner. In these 3 years images were analyzed by dedicated genitourinary radiologists and all TURBT were performed by expert urologists adhering to the European guidelines’ recommendations in order to strive for high-quality resections. Accuracy was determined using histopathology as the reference standard. Results: A total of 90 patients were analyzed, both primary and recurrent. Overall accuracy of the complete mpMRI protocol was 87% in differentiating NMIBC from MIBC. Better accuracy was achieved for ⩾25 mm (92%) and lateral wall sided (91%) lesions, while a lower one was recorded for dome tumors (86%). Hematuria, cytology, class of risks, focality and patients’ features did not impact on results. No differences were recorded for histological variants. Conclusions: mpMRI with VI-RADS showed good diagnostic performance in differentiating muscle-invasive from non-muscle-invasive bladder cancer in a real-world clinical setting. Further prospective studies with larger cohorts are warranted to confirm these findings.