How is embolization used to treat liver cancer?

Embolization is a procedure that cuts off the flow of blood in to an area that it previously supplied. Liver embolization takes advantage of the dual blood supply of the liver (hepatic artery and portal vein) and the fact the normal liver derives most of its supply from the portal vein, while cancerous tumors of the liver are supplied mainly by the hepatic artery. Therefore, you can embolize a cancerous tumor the liver while relatively sparing normal liver tissue. Another procedure called chemoembolization (CE) combines embolization with a chemotherapy agent designed to kill a particular cancerous tumor. CE is performed in patients with either primary liver cancer (aka hepatoma or hepatocellular carcinoma) or metastatic cancerous tumors that predominantly involve the liver but begin elsewhere (exs. colon cancer, breast cancer, islet cell tumors of the pancreas). The chemotherapy agent(s) are injected in to a catheter placed in a branch of an artery in the liver which is then followed by injection of particles used to cut off the blood supply behind it which locks the chemotherapy drug in with the tumor. The selective injection in to the tumor increases the amount of drug that comes in contact with the tumor as well as limiting side effects as the drug does not travel throughout the body like in a regular systemic intravenous infusion of chemotherapy. The embolization increases the time that drug stays in contact with the tumor in an attempt to optimize the effectiveness of the chemotherapy. Both the embolization and CE procedures are performed by Interventional Radiologists (IR). IRs are board-certified physicians who specialize in minimally invasive targeted treatments to treat a number of medical conditions all over the body.