Usefulness of radiofrequency ablation with micro-convex probe for hepatocellular carcinoma.

Background/Aims: It was aimed to assess whether a micro-convex probe is superior to the present conventional probe for ultrasonography from the points of safety and efficacy during percutaneous radiofrequency ablation therapy for hepatocellular carcinoma. Methodology: Twenty-one patients with 23 hepatocellular carcinoma lesions who had one or 2 lesions, each 4 cm or less in diameter, and liver function of Child-Pugh class A or B were enrolled. All the patients except for 2 patients were seropositive for hepatitis C virus. Radiofrequency ablation was carried out under a real-time US guidance. The cooled-tip electrodes used were single and clustered. Results: It was possible to perform safe and accurate percutaneous radiofrequency ablation procedure using micro-convex probes for the treatment of all hepatocellular carcinoma nodules. It was also possible to treat hepatocellular carcinoma located in the right subphrenic region without artificial pleural effusion under intercostal ultrasonography guide. Improved clustered needles were successfully applied to treat the nodules more than 3 cm in diameter with less resistance for penetration compared with the conventional needle. The findings of advanced dynamic flow image on ultrasonography to assess the therapeutic efficacy indicated the consistency with those of dynamic CT which was done 3 to 5 days later radiofrequency ablation. Major complication of radiofrequency ablation procedure was noted in none. Conclusions: These results suggest that micro-convex probe with clustered tips is superior to conventional probe for ultrasonography from the points of safety and efficacy during radiofrequency ablation for hepatocellular carcinoma nodule located in the right subphrenic region and for larger sized nodule more than 3 cm.