BJU Int. 2020 Jul 23. doi: 10.1111/bju.15188. Online ahead of print.
OBJECTIVES: (I) To determine VI-RADS score 5 accuracy in predicting locally advanced bladder cancer (BCa) as to potentially identify those patients who could avoid the morbidity of deep TURBT in favor of histologic sampling-TUR prior to radical cystectomy (RC). (II) To explore the predictive value of VI-RADS score 5 on time-to-cystectomy (TTC) outcomes.
PATIENTS AND METHODS: We retrospectively reviewed patients ineligible or refusing cisplatin-based combination neoadjuvant chemotherapy (NAC) who underwent multiparametric magnetic resonance imaging (mpMRI) of the bladder prior to staging TURBT followed by RC for muscle invasive BCa (MIBC). Sensitivity, specificity, positive and negative predictive values (PPV, NPV) were calculated for VI-RADS category 5 vs. category 2-4 cases to assess the accuracy of mpMRI for extravesical BCa detection (≥pT3). VI-RADS score performance was assessed by receiver operating characteristics (ROC) curve analysis. A Ƙ statistic was calculated to estimate mpMRI and pathologic diagnostic agreement. The risk of delayed TTC (i.e. time from initial BCa diagnosis >3 months) was assessed using an adjusted multivariable logistic regression model.
RESULTS: A total of 149 T2-T4a, cN0-M0 patients (VI-RADS score 5, n=39 vs. VI-RADS score 2-4, n=110) were examined. VI-RADS score 5 demonstrated sensitivity, specificity, PPV, and NPV, in detecting extravesical disease of 90.2% (95% confidence interval [CI]: 84-94.3), 98.1% (95% CI: 94-99.6), 94.9% (95%CI:89.6-97.6) and 96.4% (95% CI:91.6-98.6), respectively. The area under the curve (AUC) was 94.2% (95%CI: 88.7-99.7) and inter-reader agreement was excellent (Ƙinter:0.89). Mean TTC was 4.2 ± 2.3 and 2.8 ± 1.1 and months for score 5 vs. 2-4 respectively (p<.0001). VI-RADS score 5 was found to independently increase risk for delayed TTC (OR: 2.81, 95%CI: 1.20-6.62).
CONCLUSION: VI-RADS is valid and reliable in differentiating patients with extravesical disease from those with muscle-confined, BCa before TURBT. Detection of VI-RADS score 5 was found to predict significant delay in TTC independently form other clinic-pathological features. In the future, higher VI-RADS scores could potentially avoid the morbidity of extensive primary resections in favor of sampling-TUR for histology. Further prospective, larger, and multi-institutional trials are required to
validate clinical applicability of our findings.