Pathologic findings in patients with targeted magnetic resonance imaging-guided prostate needle core biopsies.

ABSTRACT

In contrast to the routine (non-targeted) sampling approach of transrectal ultrasound guided biopsies (TRUS-GB), targeted magnetic resonance imaging-guided biopsies (TMRI-GB) target regions of the prostate suspicious for prostate cancer (PCa), based on findings on multiparametric MRI. We sought to examine the pathologic findings identified on TMRI-GB, due to the fact that there are limited studies on this in the Pathology literature. A search was made through our Urologic Pathology files for prostate needle core biopsies that were obtained via TMRI-GB. Forty-six patients were identified. Mean patient (PT) age was 62 years (range 50-78 years). Twenty one of 46 PTs (46%) had a history of PCa, 10/46 PTs (22%) had a history of negative TRUS-GB and rising PSA, and the remaining 15/46 PTs (32%) had never undergone biopsy. Cancer detection rate on TMRI-GB was 57% for PTs with a prior diagnosis of PCa, 50% for PTs with a history of benign biopsy, and 67% who were biopsy naïve. An average of 3.16 cores were sampled from malignant lesions and an average of 2.74 were sampled from benign lesions (P=0.02). TMRI-GB has a higher cancer detection rate than TRUS-GB. TMRI-GB may have a critical role as a tool for active surveillance, tumor mapping, and primary detection of PCa, which will likely evolve as the ability to identify malignant lesions improve. The roles of pathologists and radiologists in the validation of this procedure will continue to be even more vital in the future.