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/mm2 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.