Brachytherapy / Internal Radiation

Systemic radiation therapy is the use of unsealed radiation sources (liquid form usually) to treat certain cancers. The radioactive sources may be taken by mouth; the doctor might inject them into a patient's body cavity or they may be given to a patient intravenously. For example, radioactive iodine (I-131) capsules are given to patients to cure their thyroid cancer. Researchers are investigating the possiblity of injecting the radioisotopes directly into a patient's tumor. Injected radioactive sources can often treat or prevnet pain due to cancer that has spread to the bone. For example, strontium-89 or samarium have been shown to be effective in treating bone pain caused by advanced prostate, breast and other cancers.

Research also is underway using radiolabeled antibodies. Some antibodies can search out and identify tumors. These antibodies are made radioactive then the radiation oncologist injects them into a patient. The radioactive antibodies search out, the tumor cells and kill them. This technique is called radio-immunotherapy.