Clinical Feasibility of 3-D Acoustic Radiation Force Impulse (ARFI) Imaging for Targeted Prostate Biopsy Guidance.

We have developed a 3-D acoustic radiation force impulse (ARFI) prostate imaging system to identify regions suspicious for cancer and guide a targeted prostate biopsy in a single visit. The system uses a side-fire transrectal probe and an automated rotation stage to acquire ARFI and B-mode image volumes, combined with 3-D visualization and targeting software to enable biopsy target identification and guide a transperineal (TP) biopsy. The system was tested in the first clinical trial of its kind, with subjects serially undergoing ARFI-guided targeted TP biopsy, multiparametric magnetic resonance imaging (mpMRI)-ultrasound fusion TP biopsy, and systematic sampling TP biopsy. The findings indicate that the ARFI system is feasible for guiding a targeted biopsy. For lower-grade cancer (grade groups [GG] 1-2), ARFI underperformed mpMRI and systematic sampling, detecting cancer in 54% of GG 2 subjects. However, ARFI performance improved with increasing cancer grade; for higher-grade cancer (GG 3-5), ARFI performed comparably to the other biopsy approaches, and detected cancer in all GG 4 and 5 subjects. The findings also suggest the benefit of using 2-D ARFI imaging to confirm target location during live B-mode imaging, which could improve existing ultrasonic fusion biopsy workflows. This study is registered with ClinicalTrials.gov as NCT04607135.