Apparent diffusion coefficient of the prostate in men prior to biopsy: determination of a cut‐off value to predict malignancy of the peripheral zone

Abstract

Determination of the apparent diffusion coefficient (ADC) of the prostate in men (n = 60) with raised prostate-specific antigen (PSA) or an abnormal digital rectal examination (DRE) prior to transrectal ultrasound (TRUS) guided biopsy using endorectal DWI is reported. Patients were categorized into different groups based on their PSA levels. The mean ADC was calculated from a number of regions of interest (ROIs) for the whole of the peripheral zone (PZ) and the central gland (CG). A total of 1108 ROIs were analyzed from 60 patients. The mean ADC value of the PZ was higher than that of the CG in controls. A total of 23 out of 60 patients were positive for malignancy on biopsy, and the mean ADC of the PZ was lower in these patients compared with those who were negative. Moreover, the mean ADC obtained for the whole of the PZ of the prostate in different groups of patients and controls showed a decreasing trend. A plot between PSA and mean ADC for the PZ showed non-linear association with logarithmic decrease in ADC. The mean ADC of the CG was not significantly different in patients who were positive or negative for malignancy in biopsy. In addition, a cut-off value of 1.17 x 10(-3) mm2/s (sensitivity = 73% and specificity = 74%, area under the curve = 0.83) for the mean ADC for the whole of the PZ of patients was determined by using the receiver operating characteristic curve (ROC) to predict malignancy of the PZ.

Comparison of PI-RADS 2, ADC histogram-derived parameters, and their combination for the diagnosis of peripheral zone prostate cancer

“…The results of histogram analyses in our study were similar to previous reports, inasmuch as clinically significant cancers had lower ADC values than MRI lesions that were not classified as clinically significant cancers in all parameters [24,25]. Yet, previous studies reported that 10th and 25th percentile ADCs tended to perform better than mean and median ADC values [13,14], while our results revealed no differences in diagnostic accuracy.…”

Role of magnetic resonance methods in the evaluation of prostate cancer: an Indian perspective

“…We assessed the potential of DWI prior to TRUS-guided biopsy in a large cohort of Indian men with a raised PSA level or an abnormal DRE [46,83]. At our institution, DW images are obtained by using a single-shot EPI sequence in the axial plane with a TR of 3000 ms; TE of 96 ms; flip angle, 90 • ; with five 'b' values of 0, 250, 500, 750 and 1,000 s/mm 2 .…”

“…With the use of endorectal MRI, the potential of diagnosis and preoperative staging has increased. Studies have been reported on the use of endorectal MRI [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], MRS and MRSI [17][18][19][20][21][22][23][24][25]29,31,32], diffusionweighted imaging (DWI) [33][34][35][36][37][38][39][40][41][42][43][44][45][46], and dynamic contrastenhanced MR imaging (DCE-MRI) [54][55][56][57][58][59][60][61][62]…”

Role of Endorectal Prostate MRI in Patients with Initial Suspicion of Prostate Cancer

“…However, the sensitivity of conventional endorectal prostate MRI in this subset of patients precludes the use of MRI alone in these patients and makes it necessary to closely monitor (e. g. by PSA testing) those who do not undergo prostate biopsy, regardless of their MRI findings. The sensitivity of conventional endorectal prostate MRI might be improved in the future by the supplementary use of newer techniques such as DWI, DCE-MRI, and 1 H-MRS [9, 26,27]. Once adequate sensitivity can be achieved with MRI, MRI findings can be used to plan targeted biopsies, thus contributing to a marked reduction of core biopsies in the future.…”