Patients with chronic hepatitis B or liver cirrhosis have hepatocellular carcinoma (HCC) (equal or less than 4 cm) which is diagnosed on contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI).

Radiofrequency ablation (RFA) will be performed by using multi-VIVA generator and Octopus electrodes. Three electrodes will be placed on the tumor under ultrasonography (US)-computed tomography (CT)/magnetic resonance (MR) fusion tool guidance. The electrodes will be cooled with saline, and radiofrequency (RF) will be applied to two of three electrodes at the same time for about 6 to 30 minutes depending on the tumor size. The temperature will be maintained at 90-100 °C. The RF energy will starts at 60 watts and increase by 10 watts every 30 seconds for the first 3 minutes, and then increases gradually by 10 watts per minute after reaching 100 watts.

Evaluate local tumor progression by follow-up computed tomography (CT) or magnetic resonance imaging (MRI) with alpha-fetoprotein (AFP) level

The cone-unit ablation is defined as complete ablation of tumor with safety margin and occlusion of the 4th or 5th branches of portal vein.