Selective internal radiation therapy for unresectable primary intrahepatic cholangiocarcinoma

2.1 Intrahepatic cholangiocarcinoma is a rare type of primary liver cancer originating in the bile ducts within the liver parenchyma. It accounts for about 10% of all cholangiocarcinomas (bile duct cancers).

2.2 Intrahepatic cholangiocarcinoma is not usually diagnosed before the symptoms of biliary obstruction occur, by which time the cancer may be too advanced for curative surgical resection. However, surgical removal with curative intent may occasionally be possible by downstaging the tumour using other types of treatment first. The standard options for palliative treatment include chemotherapy, surgical bypass of the bile duct, or inserting a stent using surgical, endoscopic or percutaneous techniques.

2.3 Selective internal radiation therapy (SIRT; also known as radio-embolisation) can be used as palliative treatment for unresectable primary liver cancer. It may also be used as a neoadjuvant treatment before surgery in patients being considered for curative treatments such as resection or liver transplantation. It aims to deliver radiation directly into the tumour, minimising the risk of radiation damage to surrounding healthy tissue.

2.4 SIRT involves delivering microspheres containing radionuclides that emit beta radiation directly into the tumour via the hepatic artery. Under local anaesthesia with fluoroscopic guidance, the radioactive microspheres, which are made of glass, resin or poly(L‑lactic) acid, are injected into branches of the hepatic artery supplying the tumour. Usually, the percutaneous femoral or radial approach is used. The microspheres are designed to lodge in the small arteries surrounding the tumour and release high doses of localised radiation directly into the tumour. The procedure may be repeated depending on the response.