Clinical Utility of VI-RADS in Diagnosis of MIBC

Bladder Cancer (BCa) is the 9th most common cancer worldwide. In general, BCa is presented as a non-muscle invasive bladder cancer (NMIBC) in 70% of patients and treated with transurethral resection of bladder tumor (TUR-BT). However, in cases of muscle invasive bladder cancer (MIBC), radical cystectomy (RC) is the gold standard of treatment. Therefore, It is important to distinguish MIBC from NMIBC. To date, pathologic staging is based on the result of TUR-BT before RC. However, it is operator dependent, thus residual cancer may be remained depending on surgical experience. Therefore, about 7%-30% patients of MIBC can be underestimated with NMIBC, and it can be increased to 45% if the muscle is not resected. Consequently, it has been raised the need for imaging test to overcome diagnostic limitations. Multiparametric magnetic resonance imaging (mpMRI) has been widely used in the field of diagnosis of BCa. In 2018, the Vesical Imaging Report and Data System (VI-RADS) was published using T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast enhanced (DCE) imaging, and 5-point VI-RADS scoring system has been proposed and reported as an imaging test useful for assessing muscle involvement in primary bladder cancer Therefore, in this study, we investigate the diagnostic performance of the VI-RADS scoring system that can differentiate NMIBC from MIBC in primary bladder cancer.