Diffusion-weighted endorectal MR imaging at 3T for prostate cancer: correlation with tumor cell density and percentage Gleason pattern on whole mount pathology

Objective To determine if tumor cell density and percentage of Gleason pattern within an outlined volumetric tumor region of interest (TROI) on whole-mount pathology (WMP) correlate with apparent diffusion coefficient (ADC) values on corresponding TROIs outlined on pre-operative MRI. Methods Men with biopsy-proven prostate adenocarcinoma undergoing multiparametric MRI (mpMRI) prior to prostatectomy were consented to this prospective study. WMP and mpMRI images were viewed using 3D Slicer and each TROI from WMP was contoured on the high b-value ADC maps (b0, 1400). For each TROI outlined on WMP, TCD (tumor cell density) and the percentage of Gleason pattern 3, 4, and 5 were recorded. The ADC mean , ADC 10th percentile , ADC 90th percentile , and ADC ratio were also calculated in each case from the ADC maps using 3D Slicer. Results Nineteen patients with 21 tumors were included in this study. ADC mean values for TROIs were 944.8 ± 327.4 vs. 1329.9 ± 201.6 mm 2 /s for adjacent non-neoplastic prostate tissue ( p