Surgical resection of the affected portion of the liver offers the best chance for disease-free survival in patients with primary liver cancer (hepatocellular carcinoma (HCC)). Unfortunately, most of these patients present with disease that is not amenable to surgery (multifocal disease) or have other medical contraindications to surgery (limited hepatic reserve related to advanced cirrhosis or chronic hepatitis). Fewer than 15% of HCC patients are suitable surgical candidates. The objective of treatment with TheraSphere is to selectively administer a potentially lethal dose of radioactive material to cancerous tissue in the liver of patients with HCC. This type of regional therapy may have several advantages over systemically administered treatments and may also be of value as a 'bridging' treatment for HCC patients awaiting a donor organ for liver transplantation.