Klin Onkol 2004; 17(5): 149-156.
Summary: Primary and secondary hepatic malignancies represent a therapeutic challenge. With its 20 % 30 % five-year survival rate, surgical resection is still considered the gold standard in treatment of hepatic malignancies, however, only less than 15 % of these patients are hepatic resection candidates. The remaining patients treated with other modalities including chemotherapy show a lower than 1 % five-year survival rate. Radiofrequency ablation (RFA) is a relatively novel treatment modality indicated in treatment of unresectable hepatic malignancies. Modern RFA systems generate a high-frequency electrical current passing through the non-insulated tip of the needle-electrode into the target tissues to cause a thermal induced coagulation necrosis. The three major brands of RFA equipment currently available are Radionics, RITA Medical System, and Radiotherapeutics. The Radionics system utilizes single or cluster Cool tip electrodes with an impedance reaction in the RFA algorithm. The other two commercial manufacturers use umbrella RFA electrodes with multiple probes and two-stage ablation option. The advantage of this ablation method lies in the possibility of a percutaneous approach, a minimally invasive laparoscopical access, or via laparotomy eventually combined with a surgical resection. The RFA indication criteria keep being evolved and are yet to be distinctly established. The goal of the method is a complete destruction of the tumor tissue. The main indication for the use of RFA is an unresectable primary or recurrent hepatic tumor. RFA should also be considered in patients unable to undergo a surgical resection via laparotomy. In case of large lesions multiple overlapping ablations are required to ensure a complete tumor destruction. However, in these cases the risk of local recurrence is significantly higher. The total number of hepatic lesions can represent a limiting indication factor as well. According to the preliminary clinical experiences published so far (Curley, Wood, Solbiati) the RFA appears to be a safe and effective method with few major complications. The authors describe the principles and indications of the RFA method, compare various approaches and indication criteria, and report the results of the initial trials.
