Contrast-enhanced Ultrasound Identifies Patent Feeding Vessels in Transarterial Chemoembolization Patients With Residual Tumor Vascularity

Transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) often requires retreatment and identification of feeding vessels supplying the residual/recurrent tumor is an important step in treatment planning. The objective of this study was to determine if contrast-enhanced ultrasound (CEUS) could correctly identify the vessel supplying the residual tumor. To date, 69 patients have undergone CEUS follow-up of HCC TACE therapy at our institution as part of an ongoing institutional review board approved trial (NCT02764801). The CEUS examinations were performed before HCC TACE as well as 1 to 2 weeks and 1 month after treatment using a Logiq E9 scanner with a C1-6 curved array transducer (GE Healthcare, Waukesha, WI). The CEUS images obtained 2 weeks after initial TACE treatment were reviewed, and any feeding vessels supplying the residual HCC were identified. Digital subtraction angiograms during the retreatment TACE were used as reference standard for feeding vessel identification. Thirteen patients with viable HCC post-TACE were included in this study. In these cases, the sonographer correctly identified 85% (11 of 13) of the feeding vessels later confirmed by angiography. Importantly, one of the false-negative cases involved a segment 8 tumor with parasitic blood supply from the medial left hepatic artery. In this case, CEUS identified a largely treated tumor with some residual internal flow, but was unable to visualize any major hepatic vascularity supplying the tumor. In conclusion, CEUS appears to be a valuable tool for planning retreatment of residual HCC post-TACE.