Planning Sonography Using Real-time Virtual Sonography and Contrast-enhanced Sonography for Radiofrequency Ablation of Inconspicuous Hepatocellular Carcinoma Nodules.

Background/aims: Determining whether planning sonography, using real-time virtual sonography (RVS) and contrast-enhanced sonography (CEUS), enables the identification of inconspicuous HCC nodules on conventional sonography (US), during percutaneous radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC).

Methodology: We examined the factors associated with poor conspicuity, identification rate of inconspicuous HCC nodules in planning US using RVS and CEUS, the success rate of RFA for such nodules and local recurrence rates.

Results: Sixty inconspicuous HCC nodules were analyzed. Factors associated with poor conspicuity included location of the nodules for 34 nodules, US findings of HCC nodules for 24 nodules, US findings of surrounding hepatic parenchyma for 26 nodules and local recurrence for 18 nodules. Fifty-five (90.0%) HCC nodules were identified with RVS. Of the remaining five HCC nodules, three were visualized with CEUS. Thus, 96.7% (58/60) of the inconspicuous HCC nodules were identified. Forty-six (79.3%) identified HCC nodules, were treated with RFA; the success rate was 95.7% (44/46). The cumulative local recurrence rates were 0%, 2.7% and 9.4% at 12, 24 and 36 months, respectively.

Conclusions: This study suggested that planning US using RVS and CEUS permits the identification of most inconspicuous HCC nodules, thereby improving the success rate of RFA.