“In-bore” MRI-guided Prostate Biopsy Using an Endorectal Nonmagnetic Device: A Prospective Study of 70 Consecutive Patients

Abstract

We investigated the diagnostic performance of in-bore endorectal magnetic resonance imaging-guided biopsy (MRI-GB) with a 1.5-T MRI scanner using a 32-channel coil in patients with suspected prostate cancer (PCa). Seventy patients with≥ 1 suspicious area found on the preliminary multiparametric MRI scan were enrolled. The index lesion was defined as the lesion with the greatest Prostate Imaging Reporting and Data System, version 2 (PIRADS-v2), score. MRI-GBs were performed with a nonmagnetic biopsy device, needle guide, and titanium double-shoot biopsy gun with dedicated software for needle tracking. Clinically significant PCa was defined as the presence of Gleason score≥ 7 in the biopsy specimen. Seventy index lesions were scheduled for MRI-GB. The median PIRADS-v2 score and the median number of cores per patient was 4 of 5 (interquartile range, 3-5) and 2 (interquartile range, 1-3), respectively. The PCa detection rate was 45.7%. Of the 70 patients, 24 (75%) had clinically significant PCa, with a significant correlation between the PIRADS-v2 score and the Gleason score in theMRI-GB cores (r= 0.839; 95% confidence interval, 0.535-0.951; P= .003). According to the PIRADs-v2 scheme, the proportion of PCa in the central and anterior regions of the gland was greater in the entire population and in the subgroup of patients with a history of negative transrectal ultrasound-guided biopsy findings (P≤ .01 for all). On multivariate analysis, a PIRADS-v2 score of 5 of 5 correlated significantly with the likelihood of PCa at biopsy (hazard ratio, 4.69; 95% confidence interval, 0.92-23.74; P= .04). No major complications were recorded. MRI-GB has a high detection rate for PCa, especially for lesions located in the central and anterior regions of the prostate.