Microwave coagulation therapy for hepatic tumors: review of the literature and critical analysis.

BACKGROUND Surgical resection of malignant hepatic tumors has been demonstrated to increase overall survival; however, the majority of patients are not candidates for resection. For patients with unresectable tumors, various chemical and thermal ablation modalities have been developed. microwave coagulation therapy (MCT) is one such thermal ablation modality and the purpose of this review is to evaluate the presently available data for MCT and assess the level of evidence to support its clinical use. METHODS This review is limited to published studies in the English literature including at least 30 patients per study with MCT for hepatocellular cancer (HCC) or colorectal hepatic metastasis (CRHM). Patterns of local recurrence, complications and survival outcome of MCT ablation are presented and discussed including assessment of Asian experience using the 2.4GHZ device and American experience using the 914MHZ device. CONCLUSIONS Although randomized controlled trials comparing RFA and MCT for hepatic ablation are lacking, our review (based on level 2 data) supports that MCT may be optimal when larger necrosis zones and/or ablation of multiple lesions are the objectives. The data support that the potential procedural advantage(s) noted for ablation of CRHM and HCC >3cm, is not supported for HCC <3cm; moreover MCT shares with all other ablation modalities a high rate of locoregional recurrence in HCC; likely due to the multicentricity of this disease process.