Contrast-enhanced ultrasound evaluation of residual blood flow to hepatocellular carcinoma after treatment with transarterial chemoembolization using drug-eluting beads: a prospective study

To evaluate the accuracy and change over time of contrast-enhanced ultrasound (US) imaging for assessing residual blood flow after transarterial chemoembolization of hepatocellular carcinoma with drug-eluting beads at 2 different follow-up intervals. Data from 16 tumors treated by transarterial chemoembolization with drug-eluting beads were successfully obtained. As part of the study, patients provided consent to undergo contrast-enhanced US examinations the morning before embolization, 1 to 2 weeks after embolization, and the morning before follow-up contrast-enhanced magnetic resonance imaging (MRI) or computed tomography (CT) (1 month after embolization). Blinded review of contrast-enhanced US and MRI/CT studies were performed by 2 radiologists who evaluated residual flow as no change, partial change, or no residual flow. Inter- and intra-reader variability rates were calculated before discordant individual reads were settled by consensus. The only adverse event reported during the contrast-enhanced US examinations was a single episode of transient back pain. Contrast-enhanced US at 1 to 2 weeks after embolization (n = 14) resulted in 100% sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Contrast-enhanced US 1 month after embolization (n = 15) resulted in 75% sensitivity, 100% specificity, 100% positive predictive value, 92% negative predictive value, and 93% accuracy. Inter-reader agreement was 86% for contrast-enhanced US at 1 to 2 weeks, 93% for contrast-enhanced US at 1 month, and 100% for contrast-enhanced MRI/CT at 1 month, whereas intra-reader agreement was 71% for contrast-enhanced US at 1 to 2 weeks, 87% for contrast-enhanced US at 1 month, and 91% for MRI/CT. Contrast-enhanced US imaging at 1 to 2 weeks after the procedure may be a viable alternative to MRI/CT for evaluating residual blood flow after transarterial chemoembolization with drug-eluting beads, albeit with a higher degree of reader variability.