Defining Novel and Practical Metrics to Assess the Deliverables of Multiparametric Magnetic Resonance Imaging/Ultrasound Fusion Prostate Biopsy

Abstract

Multiparametric magnetic resonance/ultrasound targeted prostate biopsy is touted as a tool to improve prostate cancer care and yet its true clinical usefulness over transrectal ultrasound guided prostate biopsy has not been systematically analyzed. We introduce 2 metrics to better quantify and report the deliverables of targeted biopsy. We reviewed our prospective database of patients who underwent simultaneous multiparametric magnetic resonance/ultrasound targeted prostate biopsy and transrectal ultrasound guided prostate biopsy. Actionable intelligence metric was defined as the proportion of patients in whom targeted biopsy provided actionable information over transrectal ultrasound guided prostate biopsy. Reduction metric was defined as the proportion of men in whom transrectal ultrasound guided prostate biopsy could have been omitted. We compared metrics in our cohort with those in prior reports. A total of 371 men were included in study. The actionable intelligence and reduction metrics were 22.2% and 83.6% in biopsy naïve cases, 26.7% and 84.2% in prior negative transrectal ultrasound guided prostate biopsy cases, and 24% and 77.5%, respectively, in active surveillance cases. No significant differences were observed among the groups in the actionable intelligence metric and the reduction metric (p = 0.89 and 0.27, respectively). The actionable intelligence metric was 25.0% for PI-RADS™ (Prostate Imaging Reporting and Data System) 3, 27.5% for PI-RADS 4 and 21.7% for PI-RADS 5 lesions (p = 0.73). Transrectal ultrasound guided prostate biopsy could have been avoided in more patients with PI-RADS 3 compared to PI-RADS 4/5 lesions (reduction metric 92.0% vs 76.7%, p<0.01). Our results compare favorably to those of other reported series. The actionable intelligence metric and the reduction metric are novel, clinically relevant quantification metrics to standardize the reporting of multiparametric magnetic resonance/ultrasound targeted prostate biopsy deliverables. Targeted biopsy provides actionable information in about 25% of men. Reduction metric assessment highlights that transrectal ultrasound guided prostate biopsy may only be omitted after carefully considering the risk of missing clinically significant cancers.