Image-guided percutaneous ablation therapies for hepatocellular carcinoma.

Image-guided percutaneous ablation therapies have been playing important roles in the treatment of hepatocellular carcinoma (HCC). In our department, we have treated 90% of previously untreated patients with ablation therapies. Among various local ablation therapies, radiofrequency ablation has been replacing ethanol injection as a standard therapy for patients who have unresectable HCC or who do not want surgery. Our randomized controlled trials and those of others proved that radiofrequency ablation is superior to ethanol injection. Radiofrequency ablation is potentially curative, minimally invasive, and easily repeated for recurrence. Long-term survival is notably high, and mortality and morbidity are low, in radiofrequency ablation. Further investigations are necessary to determine whether radiofrequency ablation can replace surgery for resectable hepatocellular carcinoma. In such trials, the primary endpoint must be overall survival. Recurrence-free survival can be misleading and cannot be a surrogate endpoint. There are still effective therapies after recurrence, and the first recurrence does not cause death in most cases. Furthermore, hepatectomy has theoretically better disease-free survival than radiofrequency ablation because it removes a larger amount of liver tissue. The better cure rate of resection can be canceled, however, by deterioration of liver function.