External-beam radiation therapy uses high-energy rays (or particles) to kill cancer cells or slow their growth. A carefully focused beam of radiation is delivered from a machine outside the body. This type of radiation therapy is most commonly used to treat medullary thyroid cancer and anaplastic thyroid cancer. Radioactive iodine treatment is often used to treat thyroid cancer.
The treatment is given orally. Radioactive iodine treatment reduces the risk of thyroid cancer returning. It is also used to treat thyroid cancer that spreads to other parts of the body. Medications target a specific target of cancer cells, slowing or even reversing the growth of cancer cells.
The radiation dose used here is much stronger than that used in radioactive iodine scans, which are described in Tests for Thyroid Cancer. Common types of treatment used for thyroid cancer are listed below, followed by a summary of common cancer treatments by stage of disease (see Stages). For thyroid cancer, external-beam radiation therapy is used only in certain circumstances, usually when advanced-stage thyroid cancer has spread to critical areas of the neck, such as the trachea, larynx, or esophagus. Patients with anaplastic thyroid cancer should continue to see both a doctor and a radiation oncologist.
The American Cancer Society offers programs and services to help you during and after cancer treatment. Chemotherapy is the use of drugs to kill cancer cells, usually preventing cancer cells from growing, dividing, and producing more cells. RAI builds up mainly in thyroid cells, where radiation can kill the thyroid gland and any other thyroid cells (including cancer cells) that absorb iodine, with little effect on the rest of the body. If cancer has spread beyond the thyroid to other organs, such as bones or lungs, it is called metastatic or stage IV thyroid cancer.