Quantitative diffusion-weighted imaging and dynamic contrast-enhanced MR imaging for assessment of tumor aggressiveness in prostate cancer at 3T

Purpose: To compare diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MR imaging (DCE-MRI) for characterization of prostate cancer (PC). Methods: 104 PC patients who underwent prostate multiparametric MRI at 3T including DWI and D CE-MRI before MRI-guided biopsy or radical prostatectomy. Apparent diffusion coefficient (ADC) with histogram analysis (mean, 0-25th percentile, skewness, and kurtosis), intravoxel incoherent motion model including D and f; stretched exponential model including distributed diffusion coefficient (DDC) and a; and permeability parameters including K-trans, K-ep, and V-e were obtained from a region of interest placed on the dominant tumor of each patient. Results: ADC(mean), ADC(0-25), D, DDC, and Ve were significantly lower and K-ep was significantly higher in GS >= 3 + 4 tumors (n = 89) than in GS = 3 + 3 tumors (n = 15), and also in GS >= 4 + 3 tumors (n = 57) than in GS <= 3 + 4 tumors (n = 47) (P < 0.001 to P = 0.040). f was significantly lower in GS >= 4 + 3 tumors than in GS < 3 + 4 tumors (P = 0.022), but there was no significant difference between GS = 3 + 3 tumors and GS >= 3 + 4 tumors, or between the remaining metrics in both comparisons. In metrics with area under the curve (AUC) >0.80, there was a significant difference in AUC between ADC(0-25) and D, and DDC for separating GS <= 3 + 4 tumors from GS >= 4 + 3 tumors (P = 0.040 and P = 0.022, respectively). There were no significant differences between metrics with AUC > 0.80 for separating GS = 3 + 3 tumors from GS >= 3 + 4 tumors. ADC(0-25) had the highest correlation with Gleason grade (rho =-0.625, P < 0.001). Conclusions: DWI and DCE-MRI showed no apparent clinical superiority of non-Gaussian models or permeability MRI over the mono-exponential model for assessment of tumor aggressiveness in PC.