Quantitative ultrasound assessment of transarterial radio-embolization treatment of LI-RADS 5 hepatocellular carcinoma

This prospective pilot study examines feasibility of ultrasound (US) imaging methods to evaluate patients with known HCC prior to and after treatment with transarterial radioembolization (TARE). Quantitative backscatter US (QUS) and contrast-enhanced US (CEUS) were successfully performed in the tumor and background liver, using contrast-enhanced (CE) MRI as the reference. Scans were performed pre-TARE and at 6- and 12- or 24-weeks post treatment. Enrollment of 25 patients is planned, but in 15 patients to date (age 47–94, mean 71), all were MRI LI-RADS 5 with tumor diameters 2.1–13.8 cm, had uniformly cirrhotic background liver with low steatosis. Attenuation (AC), backscatter (BC) coefficients, and envelope statistics were computed, with results in the background liver very consistent between acquisition timepoints and patients. Tumor QUS was more heterogeneous but QUS tumor-background contrast was significant. Changes in tumor AC and/or BC post-TARE were significant for all but two patients but variable. Based on MRI data, some tumors may exhibit more delayed response to TARE, so examinations at additional timepoints as well as new patient recruitment are in process. All tumor boundaries corresponded well to CEUS and CE MRI to identify tumors, demarcate tumor size, and boundaries, as well as identify response to therapy.