The Clinical Value of Radioembolization in the Treatment of Inoperable Liver Cancer

Abstract

Hepatocellular carcinoma (HCC) is a common malignancy worldwide. HCC-related mortality is high because most cases are diagnosed at an advanced stage. HCCs are relatively resistant to radiation and the liver is unable to tolerate the radiation doses required to achieve tumoricidal effects by standard external-beam radiation. Focal radiation techniques employing a 3D approach have been shown to safely permit higher levels of radiation to targeted regions within the liver. Delivery of therapy through hepatic artery branches preferentially affects HCC tumors and spares the surrounding liver parenchyma. Selective targeting of radionuclides to tumors has been shown to achieve high radiation dose ratios. Transarterial radionuclide therapies have been developed with the objective of achieving selective intra-arterial delivery of radiotherapy, including radioactive iodine-131 (131I), rhenium-188 (188Re), yttrium-90 (90Y) (resin or glass microspheres), and others. These treatments have been used to treat HCC via a selective transarterial approach as an alternative to TACE. Portal vein thrombosis (PVT) is a relative contraindication to transarterial chemoembolization (TACE); in contrast, high specific activity radiomicrospheres do not occlude a significant portion of the hepatic arterial vascular bed and can therefore be used in patients with PVT. The devices, toxicities, and results with use of the available radioembolic devices are reviewed in this article.