Hepatobiliary Malignancies

The radiosensitivity of hepatocytes and risk for radiation-induced liver disease (RILD) precluded the use of radiotherapy (RT) for liver tumors using conventional techniques. CT-based planning, stereotactic body radiation therapy (SBRT), and intensity-modulated radiation therapy (IMRT) have generated renewed interest and the growing need in the treatment of liver malignancies due to the new ability to deliver high doses to tumors with good normal tissue sparing. Though surgery is the primary treatment modality for liver tumors, RT provides previously unavailable opportunities for durable local control in patients who are inoperable or not candidates for other ablative approaches. The growing evidence of large multi-center retrospective studies and few randomized trials supports the role of RT in small HCC with non-inferior control to radiofrequency ablation and combined RT and embolization in advanced HCC with superior survival outcomes to sorafenib. Here, we review hypofractionated RT (for tumors close to bowels) and SBRT (preferred option) for hepatocellular carcinoma (HCC), cholangiocarcinoma (predominantly intrahepatic and perihilar types), and liver metastases. Though distinct clinical entities, the principles of SBRT delivery are similar. Patients with HCC may have comorbid cirrhosis which may impact treatment planning.