Microwave Ablation with Cooled-tip Electrode for Liver Cancer: an Analysis of 160 cases

Background/Aims: A novel microwave electrode with a cooled tip (FORSEA MTC-3 type, China) was devised to better enable microwave ablation of liver cancers. The efficacy of this technology was evaluated. Methodology: The records of 160 patients (97 with hepatoma/hepatocellular carcinoma, 63 with metastatic cancer to the liver) who had undergone microwave ablation with this new device were reviewed. One year survival in 86 patients whose follow-up had been more than one year was determined. Preoperative and post-operative contrast-enhanced CT scans were performed to assess completion of therapy and the presence or absence of recurrent tumor. For patients with hepatoma/hepatocellular carcinoma, serum AFP levels were evaluated pre-operatively and, if elevated, post-operatively. Results: A mean 2.2 (range 1-5) applications were required per session. All patients exhibited initial radiographic resolution of their lesions after therapy. The ablated areas were not enhanced in every phases of contrast CT scan. Eight patients required a second microwave therapy for recurrent tumor; two patients required a third treatment. Twenty five patients with hepatoma/hepatocellular carcinoma had elevated AFP (104.2 +/- 22.5 ng/ml), which, after microwave ablation, recovered to normal or almost normal (24.6 +/- 3.6 ng/ml) (t=2.1, p<0.05). There were no post-operative deaths. Complications included fever in three of four patients, successfully treated with indomethacin, elevated transaminases in four of five patients, requiring no treatment except for those with pre-operative ascites (who were dialyzed), pleural effusions in fourteen patients, only one of whom required drainage, and obstructive jaundice requiring drainage in two patients. The one year fraction was 91.9%. Conclusions: Microwave ablation with this novel cooled-tip electrode is safe, minimally invasive and effective. The tool may greatly expand the fraction of patients with liver cancer who might be candidates for microwave ablation.