EAU 2017: Controversies in prostate cancer detection: Biparametric MRI is enough

London, England (UroToday.com) In this spirited session, Dr. Pinto acknowledged that mpMRI has improved biopsy decision making and the yield of clinically significant prostate cancer, albeit with the caveat of significant cost and time. On the other hand, bMRI (T2W and diffusion-weighted imaging (DWI)) can give a “quick, 15 minute, no frills MRI of the prostate” as Dr. Pinto describes. Dr. Pinto elegantly described how when he started in the prostate imaging arena nearly 20 years ago, he wanted “everything” that an MRI had to offer, namely T2, DWI, diffusion contrast enhancement (DCE), and spectroscopy. Over time it became evident to Dr. Pinto that MR-spectroscopy was costly and added very little to the clinical picture. Since then he has also advocated for only utilization of DCE (ie mpMRI) for challenging cases.

In work from his group at the NCI [1], they assessed 143 men with PSA, PSA-density, DRE mpMRI, bMRI, and MRI targeted prostate biopsy + 12 core TRUS biopsy and found that bMRI performed well for the detection of prostate cancer (area under the curve (AUC) 0.80), compared to PSA (AUC 0.66) and PSA-density (AUC 0.74). Dr. Pinto also highlighted that in a recent study [2] assessing 161 men with clinical suspicion of prostate cancer, bMRI also performed well. Cognitive targeted biopsy based off of bMRI findings compared to standard template biopsy detected more significant prostate cancer, while detecting less Gleason 6 prostate cancer.

Dr. Pinto thinks that bMRI should be considered the prostate MRI imaging modality of choice when clinically indicated for a number of reasons, including cost effectiveness. Second, from a patient perspective he states that a number of patients are increasingly concerned with IV gadolinium required for DCE imaging. When questioned from the audience regarding why we are “taking a step back from everything being toward mpMRI” only a few years ago, Dr. Pinto thinks this is secondary to improved image quality of T2 and DWI images, and education of both urologists and radiologists. When questioned regarding how bMRI and mpMRI may coexist in future clinical practice, both Drs. Futterer and Pinto feel that bMRI may be used as an initial imaging modality and mpMRI reserved for equivocal findings and/or challenging cases.

1. Rais-Bahrami S, Siddiqui MM, Vourganti S, et al. Diagnostic value of biparametric magnetic resonance imaging (MRI) as an adjunct to prostate-specific antigen (PSA)-based detection of prostate cancer in men without prior biopsies. BJU Int 2015;115(3):381-388.
2. Jambor I, Bostrom PJ, Taimen P, et al. Novel biparametric MRI and targeted biopsy improves risk stratification in men with a clinical suspicion of prostate cancer (IMPROD Trial).

Presented by: Peter A. Pinto, National Cancer Institute, Bethesda, USA

Written by: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto
Twitter: @zklaassen_md

at the #EAU17 -March 24-28, 2017- London, England