Apparent Diffusion Coefficient Value and Ratio as Noninvasive Potential Biomarkers to Predict Prostate Cancer Grading: Comparison With Prostate Biopsy and Radical Prostatectomy Specimen

OBJECTIVE. The purpose of this study is to test the association between diffusion-weighted MRI and prostate cancer Gleason score at both biopsy and final pathologic analysis after radical prostatectomy. SUBJECTS AND METHODS. Patients with prostate cancer (n = 72) underwent diffusion-weighted MRI (b values, 0, 800, and 1600 s/mm2) with an endorectal coil. Apparent diffusion coefficient (ADC) and ADC ratio were obtained in normal and pathologic tissue and were correlated with transrectal ultrasound–guided biopsy (n = 72) and histopathologic (n = 39) Gleason scores using the ANOVA test. ADC accuracy was estimated using ROC curves. RESULTS. Lesions suspicious for prostate cancer were detected in 65 patients. The mean ADC was 1.47 and 0.87 × 10−3 mm2/s for normal and pathologic tissue, respectively (p < 0.001). When we divided the population into four groups (normal tissue and biopsy Gleason scores of 6, 7, and 8–10), then the mean ADC value was 1.47, 0.96, 0.80, and 0.78 × 10−3 mm2/s, respectively (p < 0.001)...