Stereotactic body radiation therapy for primary hepatic malignancies and metastases to liver: a technical and literature review

The management of hepatic malignancies presents several unique challenges to providers. Surgical resection is the standard of care, but less than 30% of tumors are amenable to resection at the time of diagnosis. In primary malignancies, such as hepatocellular carcinoma (HCC), orthotopic liver transplantation (OLT) is the only other curative option when a lesion is deemed unresectable. For this reason, various alternative local and regional therapies such as chemoembolization, radioembolization with Yttrium-90 microspheres, and radiofrequency ablation (RFA) have been used to prevent disease progression, palliate symptoms, and to delay liver failure. Historically, radiation has played a limited role in the treatment of hepatic malignancies. Recently, however, stereotactic body radiation therapy (SBRT) has emerged as a non-surgical, non-invasive alternative local therapy for both primary and metastatic hepatic malignancies. Over the past decade, several studies have evaluated the use of SBRT in the treatment of liver malignancies, and have shown that, with appropriate patient selection, SBRT can provide a safe and effective alternative to surgery. This review discusses the application of SBRT in both primary hepatic malignancies and metastases to the liver, highlighting the current literature and future directions.