Radiation therapy is one way in which many different kinds of cancers can be treated. Radiation causes cell damage; if properly focused, it will mainly destroy cancer cells, though normal cells may also be affected. There are several different forms of radiation treatment used in cancer treatment; the form used depends on the type of cancer.
External Beam Radiation
External beam radiation therapy is one of the most common forms of radiation treatment used for cancer. With this kind of therapy, subatomic particles are energized so that they move very quickly using a device known as a linear accelerator, the American Cancer Society explains. These particles are then carefully aimed at the cancerous tissue, so that as much of the radiation hits tumor cells instead of healthy cells. Once these particles hit the cells, they can damage the cells' membranes, genetic material and proteins, ultimately causing cell death. There are several different kinds of subatomic particles that can be used. High energy photons are the most common. Electrons can also be used; these particles are used to treat cancerous tissue near the body's surface because they do not penetrate far into the body. Protons are useful because they cause less damage to tissues through which they pass; instead, these particles only cause significant damage to the tissues in which they embed. Neutrons can also be used for cancers of the prostate, neck and head, though their use has declined because they cause more serious side effects.
Brachytherapy
Brachytherapy is a form of radiation treatment in which a small amount of radioactive material is surgically implanted in or near a tumor, notes the "Journal of the American Medical Association." The brachytherapy material can come in the form of a small pellet or a series of wires. The radioactive material may be left in permanently or removed after a short period of time. The materials used for brachytherapy are designed to provide radioactive particles that only are able to travel a short distance. This means that higher doses of radiation can be used without causing dangerous side effects.
Systemic Radiation Therapy
Systemic radiation therapy involves the administration of radioactive materials either orally or via injection. Typically, according to the National Cancer Institute, strongtium-89 or iodine-131 are used for this purpose. This kind of therapy is typically used to treat certain kinds of lymphoma and thyroid cancer, because the administered materials will naturally collect in the cancerous tissue, resulting in cancer cells being predominantly affected by the radiation.
