Apparent diffusion coefficient value reflects invasive and proliferative potential of bladder cancer. Issue 1 (15th April 2013) - Kobayashi, Shuichiro
Abstract : Purpose: To elucidate a role of apparent diffusion coefficient (ADC) value as a biomarker of bladder cancer, we investigated its associations with Ki‐67 labeling index (LI) along with classical clinicopathological prognosticators. Materials and Methods: Diffusion‐weighted MRI (DW‐MRI) at 1.5 Tesla using b ‐values of 0, 500, 1000, and 2000 s/mm 2 was prospectively taken before transurethral resection by 132 bladder cancer patients. ADC value of index tumors was measured and compared with clinicopathological prognosticators including Ki‐67 LI. Results: ADC value was significantly lower in tumors with higher Ki‐67 LIs, sessile tumors (versus papillary), larger tumors, higher grade disease, and higher T stage disease. ADC value inversely correlated with Ki‐67 LI (ρ = −0.57; P < 0.0001). On multiple regression analysis, T stage and Ki‐67 LI significantly correlated with ADC value. The Akaike information criterion confirms these two parameters constitute the best model for determining ADC value. Similarly, T stage and ADC value significantly correlated with Ki‐67 LI and these two parameters composed the best model for predicting Ki‐67 LI. Conclusion: ADC value would reflect T stage and Ki‐67 LI, representing invasive and proliferative potential, respectively. ADC value is likely to serve as a biomarker reflecting aggressiveness of bladder cancer. J. Magn. Reson. Imaging 2014;39:172–178. © 2013 Wiley Periodicals, Inc.