Radiation therapy for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide, and its incidence is on the rise. The primary therapy is resection or liver transplant, but only a minority of patients present with resectable disease. Historically, radiotherapy has not played a significant role in the treatment of liver malignancies because of the low tolerance of the whole liver to radiation. With improvements in 3-dimensional conformal radiotherapy and intensity-modulated radiotherapy, higher doses of radiation can be delivered to target lesions with low doses to the noninvolved liver; thus, experience in the use of radiation for the treatment of focal HCC has increased. At the same time, our understanding of the relationships between radiation dose and volume and the risk of classic radiation-induced liver disease and other toxicities more likely to occur in HCC patients has improved considerably. These developments have led to a body of evidence that now supports the careful use of radiotherapy for unresectable HCC. The rationale for studying radiotherapy in a randomized trial is strong.