Radiofrequency Thermal Ablation of Metastatic Liver Tumors: Usefulness of Combined Chemotherapy

ABSTRACT

PURPOSE: To assess the usefulness of radiofrequency (RF) thermal ablation with combined chemotherapy for the treatment of metastatic liver tumors. MATERIALS AND METHODS: A non-randomized, comparative study was performed in 21 patients with metastatic liver tumors. Inclusion criteria were that these should be less than five in number and less than 6 cm in diameter. Two groups were designed for comparison of the local and remote (new intrahepatic or extrahepatic) tumor control rate (Group A RF alone, n=11; Group B RF+combined chemotherapy, n=10). There was no significant difference in age, sex, and mass size between the two groups (p>0.05). All ablations were performed percutaneously with a 50W RF generator and 15G-needle electrode (RITA Medical System Inc.) under US guidance. In group B, six cycles of systemic chemotherapy were performed every month immediately after RF ablation. Follow-up CT scans were obtained within 24 hours of ablation and were compared with the findings of pre-ablation CT scanning. If an ablated lesion covered the mass without any residual enhancing foci, this was defined as complete ablation. Three and six months after ablation, local and remote tumor control rates were compared between the two groups (follow up range 4 -17 (mean, 10.2) months. RESULTS: In group A, the local tumor control rate was 43.8% (7/16) and 31.2% (5/16) at 3 and 6 months follow-up, respectively, while in group B, the corresponding rates were both 75% (15/20). At three months, the difference in this rate between the two groups was not significantly different (p>0.05), but at 6 months there was significant difference (p<0.05). At 6 months follow-up, the remote tumor control rate for Group A and Group B was 27.3% (3/11) and 80.0% (8/10), respectively, reflecting a significant difference between the two groups (p<0.05). CONCLUSION: In patients with metastatic liver tumor, radiofrequency thermal ablation with combined chemotherapy may be superior to RF thermal ablation alone for both local and remote tumor control.