Background: The majority of patients with primary or metastatic malignancies confined to the liver are not candidates for resection because of tumor size, location, multifocality, or inadequate functional hepatic reserve. Cryoablation has become a common treatment in select groups of these patients with unresectable liver tumors. However, hepatic cryoablation is associated with significant morbidity. Radiofrequency ablation (RFA) is a technique that destroys liver tumors in situ by localized application of heat to produce coagulative necrosis. In this study, we compared the complication and early local recurrence rates in patients with unresectable malignant liver tumors treated with either cryoablation or RFA.
Patients and methods: Patients with hepatic malignancies were entered into two consecutive prospective, nonrandomized trials. The liver tumors were treated intraoperatively with cryoablation or RFA; intraoperative ultrasonography was used to guide placement of cryoprobes or RFA needles. All patients were followed up postoperatively to assess complications, treatment response, and local recurrence of malignant disease.
Results: Cryoablation was performed on 88 tumors in 54 patients, and RFA was used to treat 138 tumors in 92 patients. Treatment-related complications, including 1 postoperative death, occurred in 22 of the 54 patients treated with cryoablation (40.7% complication rate). In contrast, there were no treatment-related deaths and only 3 complications after RFA (3.3% complication rate, P<0.001). With a median follow-up of 15 months in both patient groups, tumor has recurred in 3 of 138 lesions treated with RFA (2.2%), versus 12 of 88 tumors treated with cryoablation (13.6%, P<0.01).
Conclusions: RFA is a safe, well-tolerated treatment for patients with unresectable hepatic malignancies. This study indicates that (1) complications occur much less frequently following RFA of liver tumors compared with cryoablation of liver tumors, and (2) early local tumor recurrence is infrequent following RFA.