The ultrasound characteristics of regions identified as suspicious by magnetic resonance imaging (MRI) predict the likelihood of clinically significant cancer on MRI–ultrasound fusion-targeted biopsy

Objective: To determine whether the presence of an ultrasound hypoechoic region at the site of a region of interest (ROI) on magnetic resonance imaging (MRI) results in improved prostate cancer (PCa) detection and predicts clinically significant PCa on MRI–ultrasonography fusion-targeted prostate biopsy (MRF-TB). Materials and Methods: Between July 2011 and June 2017, 1058 men who underwent MRF-TB, with or without systematic biopsy, by a single surgeon were prospectively entered into an institutional review board-approved database. Each MRI ROI was identified and scored for suspicion by a single radiologist, and was prospectively evaluated for presence of a hypoechoic region at the site by the surgeon and graded as 0, 1 or 2, representing none, a poorly demarcated ROI-HyR, or a well demarcated ROI-HyR, respectively. The interaction of MRI suspicion score (mSS) and ultrasonography grade (USG), and the prediction of cancer detection rate by USG, were evaluated through univariate and multivariate analysis. Results: For 672 men, the overall and Gleason score (GS) ≥7 cancer detection rates were 61.2% and 39.6%, respectively. The cancer detection rates for USGs 0, 1 and 2 were 46.2%, 58.6% and 76.0% (P < 0.001) for any cancer, and 18.7%, 35.2% and 61.1% (P < 0.001) for GS ≥7 cancer, respectively. For MRF-TB only, the GS ≥7 cancer detection rates for USG 0, 1 and 2 were 12.8%, 25.7% and 52.0%, respectively (P < 0.001). On univariate analysis, in men with mSS 2–4, USG was predictive of GS ≥7 cancer detection rate. Multivariable regression analysis showed that USG, prostate-specific antigen density and mSS were predictive of GS ≥7 PCa on MRF-TB. Conclusions: Ultrasonography findings at the site of an MRI ROI independently predict the likelihood of GS ≥7 PCa, as men with a well-demarcated ROI-HyR at the time of MRF-TB have a higher risk than men without.