Japanese experience in ablation therapies for hepatocellular carcinoma.

In the treatment of hepatocellular carcinoma, only 20-30% of patients are candidates for surgery. Still worse, even after curative surgical resection, 80% of patients develop recurrence within 5 years. Thus, various non-surgical therapies have developed. Among them, image-guided local ablation therapies, such as percutaneous ethanol injection, microwave coagulation and radiofrequency ablation, have been widely used for small hepatocellular carcinoma, because they are potentially curative, minimally invasive and easily repeatable. Percutaneous ethanol injection was a standard therapy. However, there has been a drastic shift from ethanol injection to radiofrequency ablation in recent years. In Japan, 1500 institutes have already introduced radiofrequency ablation in the treatment of liver tumors and the cool-tip electrode system has an 80% share of the market. Radiofrequency ablation can achieve complete tumor necrosis in most cases.Long-term survival seems considerably good, and complications are not frequent in radiofrequency ablation. Randomized controlled trials have proved that radiofrequency ablation is superior to ethanol injection in the treatment of small hepatocellular carcinoma from the viewpoint of, not only treatment response, but also long-term survival. Radiofrequency ablation seems feasible, efficacious and considerably safe. Radiofrequency ablation will be more widely performed in the treatment of primary and metastatic liver tumors in Japan.