Overview: Where does radiation therapy fit in the spectrum of liver cancer local-regional therapies?

Experience with radiation therapy for the treatment of hepatocellular carcinoma (HCC) and liver metastases has increased rapidly in the past decade. This is principally because of advances in imaging and radiation techniques that can conform high doses to focal cancers and to a better understanding of how to avoid radiation-induced liver toxicity. Guidelines on how to use radiation therapy safely are becoming more clearly established, and reports of tumor control at 2 to 5 years show the potential for cure after radiation therapy for early-stage HCC and liver metastases. For both HCC and liver metastases, the best outcomes after radiation therapy are found in patients with fewer than 3 lesions that are <6 cm in size, with intact liver function and no extrahepatic metastases. There is a strong rationale for using radiation therapy in patients unsuitable for or with expected poor outcomes after standard local-regional therapies. These patients tend to have advanced tumors (large, multifocal, or invading vessels) and/or impaired liver function, reducing the chance of cure and increasing the chance of toxicity. In these patients, the benefits of radiation therapy over systemic therapy or best supportive therapy should be established in randomized trials.