Radiofrequency Ablation of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant neoplasms in the world and is the main cause of death in patients with liver cirrhosis. Surgical treatments including hepatic resection and liver transplantation are considered as the most effective treatment of HCC, however for various reasons, the vast majority of HCC patients are not suitable for surgery. Radiofrequency ablation (RFA) is a local ablation technique designed to destroy the tumor by heating. Alternating current passing from an electrode into the surrounding tissue causes ions to vibrate and generate heat in the tissue. Increased current leads to more vigorous ionic motion and increased temperature over a period of time, eventually leading to coagulation necrosis and cell death. The purpose of RFA treatment is complete tumor ablation with a margin of apparently normal tissue without collateral damage. The efficacy of RFA can be assessed with contrast-enhanced ultrasound, contrast-enhanced dynamic CT (CECT) or contrast-enhanced magnetic resonance imaging (MRI). A successful RFA treated area of HCC is nonenhancing on CECT and tends to be larger than the original tumor. A recent ablation area may have a circumferential rim of peripheral hyperemia from the host inflammatory response to thermal injury, which usually subsides a month after RFA. Discrete nodular noncircumferential enhancement, especially at the ablation margin, would raises suspicions of residual or recurrent tumors. The result of percutaneous RFA in the treatment of patients with HCC is very promising. The tumor size and the Child-Pugh class are two significant predictors of survival in RFA-treated patients. Comparative studies with surgical resection showed a promising survival rates with lower complication comparable to those of surgical resection. The complication rate following RFA varies from 2 to 10.6% and the mortality from 0 to 1.4%. In conclusion, RFA is a safe and highly effective treatment of HCC, especially for small tumors less than 3 cm in size. RFA technology and applications have progressed dramatically in the last few years. There are now well-documented roles for its use in a variety of circumstances. Although surgery is still the recommended treatment modality in patients with HCC, the majority of these patients are not surgical candidates. In the future RFA will likely play a significant role with a potential curative intent in the patients with HCC