Figure 1.

Appearance of PEI-RFA treatment. A 17-gauge RFA needle with 2 or 3 cm electrode was first inserted into the tumor through the hole of the attachment beside the echo probe, and then 21-gauge PEI needle was inserted through the same hole. RFA was performed immediately after injecting the ethanol into the tumor. The ablation was performed under the impedance control. The amount of ethanol injected into the tumors was always kept below the double of the estimated tumor volume and the injection of ethanol was ceased if resistance to the injection was felt.