Multiple-electrode radiofrequency ablation of hepatic malignancies: initial clinical experience.

OBJECTIVE: The objective of our study was to retrospectively analyze our initial clinical experience with percutaneous multiple-electrode radiofrequency ablation and evaluate its safety and efficacy for treating hepatic malignancies.
MATERIALS AND METHODS: Thirty-eight malignant hepatic tumors (mean diameter, 2.7 cm; range, 0.7-10.0 cm) in 23 patients (12 men and 11 women; mean age, 65 years; range, 40-84 years) were treated in 26 radiofrequency ablation sessions with an impedance-based multiple-electrode system. One, two, or three (mean, 2.4) 17-gauge electrodes were placed, and tumors were ablated using a combination of CT and sonography for guidance and monitoring. Electrodes were placed in close proximity (mean spacing: two electrodes, 1.0 cm; three electrodes, 1.4 cm) to treat large tumors or were used independently to treat several tumors simultaneously. Contrast-enhanced CT scans were obtained immediately after ablation to determine technical success and evaluate for complications. Follow-up CT scans at 1, 3, 6, 9, and 12 months (mean, 4 months) after ablation were obtained to assess for tumor progression and new metastases.
RESULTS: Local control was achieved in 37 of 38 tumors, 34 of which were treated in one session. Ablations created with closely spaced electrodes had a mean diameter of 4.9 cm. The total ablation time was reduced by approximately 54% compared with an equivalent number of ablations performed with a single-electrode system (1,014 vs 2,196 minutes). Three complications occurred: one death from a presumed postprocedure pulmonary embolus, one pneumothorax, and one asymptomatic perihepatic hemorrhage.
CONCLUSION: Multiple-electrode radiofrequency ablation appears to be a safe and effective means of achieving local control in large or multiple hepatic malignancies at short-term follow-up.