Treatment of hepatocellular carcinoma with percutaneous radiofrequency ablation: usefulness of contrast harmonic sonography for lesions poorly defined with B-mode sonography.

OBJECTIVE: The purpose of this study was to assess the usefulness of contrast harmonic sonography guidance in percutaneous radiofrequency ablation of hepatocellular carcinomas that could not be adequately depicted by B-mode sonography. SUBJECTS AND METHODS. Twenty-one patients with 21 hepatocellular carcinomas prospectively underwent radiofrequency ablation treatment with contrast harmonic sonography as guidance. Twenty-five patients with 25 hepatocellular carcinomas were retrospectively selected as the historical control group under the same conditions as the study group; the control group patients were treated under B-mode sonography guidance.

RESULTS: Twenty (95.2%) of the 21 patients were successfully treated during a single treatment session, and the remaining patient (4.8%) required two treatment sessions with contrast harmonic guidance. On the other hand, only eight (32%) of the 25 control subjects were successfully treated during a single treatment session using B-mode sonographic guidance without contrast imaging. The difference between these two groups was statistically significant (p = 0.002).

CONCLUSION: Contrast harmonic sonography helps in the placement of radiofrequency ablation electrodes in hypervascular hepatocellular carcinomas that cannot be adequately depicted by B-mode sonography.