Evaluation of therapeutic response using Sonazoid-enhanced ultrasonography after radiofrequency ablation of hepatocellular carcinoma. Comparison with dynamic CT

The purpose of this study was to assess the reliability of Sonazoid-enhanced ultrasonography (SEUS) in evaluating the therapeutic response of percutaneous radiofrequency ablation (RFA) in patients with hepatocellular carcinoma (HCC). Seventy consecutive nodules were examined using SEUS and dynamic computed tomography (CT) after RFA. Therapeutic response was classified into 4 grades (R grades) according to the extent and pattern of ablated areas around the nodule. R numbers were compared between SEUS and dynamic CT, as the current standard method. The consistency ratio of R grades was 50% and the weighted kappa coefficient was 0.49. Consistency ratio for decision-making concerning the requirement for additional RFA was 73%. We were able to depict ablated tumors in ablated areas in 16 nodules. In these nodules, the consistency ratio was 70% and weighted kappa coefficient was 0.75 compared with limitations of nodules, which were depicted in ablated areas on dynamic CT by Lipiodol injected prior to RFA. SEUS offers high diagnostic agreement with dynamic CT in assessing the therapeutic effects for decision-making concerning requirements for additional RFA. In particular with nodules depicted in the ablated area, SEUS may provide alternative approaches to dynamic CT with Lipiodol injection prior to RFA. (author)