RESUMO
Incidence of primary and secondary liver tumors is increasing. Hepatic resection remains the treatment of choice for hepatic tumors. For various reasons the vast majority of patients with liver tumors are not suitable for resection. These patients are candidates for several image-guided focal thermal ablative therapies as alternatives to resection. Currently available ablative techniques include cryotherapy, radiofrequency ablation (RFA), microwave ablation (MWA), laser ablation, high-intensity focused ultrasound ablation (HIFU), and ethanol injection. Presently RFA is most widely heat-based technology used for treatment of liver malignancies due to its availability, efficacy and low complication rates. However, RFA can be time-consuming and associated with higher recurrence rates in larger lesions. MWA is a new thermal ablative technique that uses electromagnetic energy to produce coagulation necrosis. MWA has several advantages over RFA such as an improved convection profile, consistently higher intratumoral temperatures, larger ablation volumes, faster ablation times, and the option of using multiple antennae simultaneously. We report our first experience using MWA and a Coviden Valleyab 915 MHz generator for ablation of liver tumor with respect to our previous experience with RFA. Further this study reviews current literature on the RFA and MWA for the treatment of the liver malignances. In our opinion although experience is limited MWA appears to be a safe and effective technology for hepatic tumor ablation and in some cases may be superior alternative to RFA.
