Surgery is the most common treatment of cancer of the thyroid. A doctor may remove the cancer using one of the following operations: Lobectomy removes only the side of the thyroid where the cancer is found. Lymph nodes in the area may be taken out (biopsied) to see if they contain cancer. Near-total thyroidectomy removes all of the thyroid except for a small part. Total thyroidectomy removes the entire thyroid. Lymph node dissection removes lymph nodes in the neck that contain cancer. Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation for cancer of the thyroid may come from a machine outside the body (external radiation therapy) or from drinking a liquid that contains radioactive iodine. Because the thyroid takes up iodine, the radioactive iodine collects in any thyroid tissue remaining in the body and kills the cancer cells. Hormone therapy uses hormones to stop cancer cells from growing. In treating cancer of the thyroid, hormones can be used to stop the body from making other hormones that might make cancer cells grow. Hormones are usually given as pills. Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in the vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells outside the thyroid.