Utility of Restriction Spectrum Imaging Among Men Undergoing First-Time Biopsy for Suspected Prostate Cancer.

OBJECTIVE. The purpose of this article is to evaluate restriction spectrum imaging (RSI) in men undergoing MRI-ultrasound fusion biopsy for suspected prostate cancer (PCa) and to compare the performance of RSI with that of conventional DWI. MATERIALS AND METHODS. One hundred ninety-eight biopsy-naïve men enrolled in a concurrent prospective clinical trial evaluating MRI-targeted prostate biopsy underwent multiparametric MRI with RSI. Clinical and imaging features were compared between men with and without clinically significant (CS) PCa (MRI-ultrasound fusion biopsy Gleason score ≥ 3 + 4). RSI z score and apparent diffusion coefficient (ADC) were correlated, and their diagnostic performances were compared. RESULTS. CS PCa was detected in 109 of 198 men (55%). Using predefined thresholds of ADC less than or equal to 1000 μm2/s and RSI z score greater than or equal to 3, sensitivity and specificity for CS PCa were 86% and 38%, respectively, for ADC and 61% and 70%, respectively, for RSI. In the transition zone (n = 69), the sensitivity and specificity were 94% and 17%, respectively, for ADC and 59% and 69%, respectively, for RSI. Among lesions with CS PCa, RSI z score and ADC were significantly inversely correlated in the peripheral zone (ρ = -0.4852; p < 0.01) but not the transition zone (ρ = -0.2412; p = 0.17). Overall diagnostic accuracies of RSI and DWI were 0.70 and 0.68, respectively (p = 0.74). CONCLUSION. RSI and DWI achieved equivalent diagnostic performance for PCa detection in a large population of men undergoing first-time prostate biopsy for suspected PCa, but RSI had superior specificity for transition zone lesions.

AJR. American journal of roentgenology. 2019 Apr 30 [Epub ahead of print]

Ely R Felker, Steven S Raman, Sepideh Shakeri, Sohrab A Mirak, Amirhossein M Bajgiran, Lorna Kwan, Pooria Khoshnoodi, Fuad F ElKhoury, Daniel J A Margolis, David Karow, David S K Lu, Nate White, Leonard S Marks

1 Department of Radiology, Ronald Reagan UCLA Medical Center, 757 Westwood Blvd, Ste 1638, Los Angeles, CA 90095., 2 Department of Urology, Ronald Reagan UCLA Medical Center, Los Angeles, CA., 3 Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN., 4 Department of Radiology, Weill Cornell Medical College, New York, NY., 5 Human Longevity, Inc., San Diego, CA., 6 Department of Radiology, University of California San Diego, San Diego, CA.