In embolization, small particles called microspheres are injected into the hepatic artery to stop the flow of blood to the tumor. Since a tumor needs oxygen and nutrients in order to grow, embolization "starves" the tumor and arrests its growth. Embolization is a good option for patients whose tumors are inoperable. It is also effective in treating larger (greater than 2 inches) tumors. During the procedure, a doctor places a catheter into an artery in the thigh and threads it up into the hepatic artery. Once the catheter arrives at the liver, the doctor injects microspheres to block the artery.
Sometimes, embolization is used to administer chemotherapy or radiation. In chemoembolization, the doctor coats the microspheres with chemotherapy drugs before injecting them into the catheter. This is a fast and effective means of administering chemotherapy, because it is so targeted and concentrated. In radioembolization, the doctor injects radioactive beads or oils into the catheter so that the radiation is released directly into the tumor without damaging healthy tissue.