Selective Internal Radiation Therapy (SIRT) is a way to use radiotherapy to treat liver cancer that cannot be removed with surgery or local ablative techniques such as radiofrequency ablation. This means the radiation is delivered into or close to the tumor(s), rather than delivered from outside the body. Yttrium 90 microspheres used in SIRT are extremely small (20-60 microns; about one-third the diameter of a strand of hair) beads which contain the radioactive substance yttrium-90 (Y-90). Because of their small size, the microspheres enter the small blood vessels of the tumor. Radioactivity is delivered directly to the tumor tissue.
Due to the unique blood supply of the liver, Y-90 microspheres can be delivered directly into the liver tumors. This targeted treatment allows maximum radiation doses to be administered to the liver while reducing exposure to the remaining healthy tissue. The microspheres are small enough to flow through the hepatic arteries, but they are too large to pass through the small blood vessels within the tumor, where they become permanently lodged in the tumor bed.
Our Y-90 team will collect about your previous cancer history and any other medical conditions. Then, we will conduct a number of initial tests to ensure that it is possible for patients to receive SIRT safely. Normally patients will undergo two procedures under conscious sedation. Both procedures will include a radiology procedure known as an angiogram. The purpose of the first angiogram or mapping is to prepare liver for the SIRT treatment. Patients will also receive a small amount of radioactive ‘test beads’ to check any amount of flow of beads from the liver to the lungs. Assuming that the results of these initial tests are acceptable, the dose of Y-90 microspheres will be determined. The Y-90 microspheres will then be administered during a second procedure which is typically conducted one to two weeks after the initial tests are completed.
The Y-90 team of Taipei VGH has finished the procedure more than 600 cases that have liver cancer or colon cancer. The procedure also has quite a good result on neuroendocrine tumor and cholangiocarcinoma. In 2011, we applied a technique combined angiography and computerized tomography (CT) as well as cone-beam CT, in order to know the physical information of patients accurately and assist the Y-90 team to make a comprehensive care plan to get the best benefit on patients. As we are one of the most experienced Y-90 centers in Asia, lots of foreign institutes have visited our hospital to learn and exchange the experiences. The Y-90 team keeps striving to achieve the best international position in this specialty.