Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. Radiation therapy may be given after surgery to kill any thyroid cancer cells that were not removed. Types of radiation therapy include:
- External radiation (or external beam radiation) comes from a machine outside the body. The machine directs high-energy rays at the cancer and some normal surrounding tissue. It is the most often used radiation treatment. The machine used to deliver the high-energy rays is called a linear accelerator.
- Three-dimensional (3-D) conformal radiation treatment is a type of external beam radiation. It uses computers to allow doctors to more precisely target a tumor with radiation beams (using width, height, and depth).
- Intensity-modulated radiation treatment (IMRT) is a type of 3-D conformal radiation treatment that uses radiation beams (usually x-rays) of various intensities to give different doses of radiation, at the same time, to small areas of tissue. This allows the delivery of higher doses of radiation to the tumor and lower doses to nearby healthy tissue.
- Internal radiation treatment, or brachytherapy is given by placing an implant into or near the tumor. The implant is a small container that holds the radioactive source or material. Internal radiation treatment allows your doctor to give a higher total dose of radiation to a smaller area and in a shorter time than with external radiation treatment.
- Proton therapy is the most precise form of radiation treatment for cancer possible, while minimizing damage to healthy tissue and surrounding organs.
Follicular thyroid (cancer that forms in follicular cells in the thyroid and papillary thyroid cancers (cancer that forms in follicular cells in the thyroid) are sometimes treated with radioactive iodine (RAI) therapy.
For imaging tests, the patient takes a small dose of radioactive iodine that collects in thyroid cells and certain kinds of tumors and can be detected by a scanner. To treat thyroid cancer, the patient takes a large dose of radioactive iodine, which kills thyroid cells. Radioactive iodine is given by mouth as a liquid or in capsules, by infusion, or sealed in seeds, which are placed in or near the tumor to kill cancer cells.
Higher doses than the amounts used to diagnose thyroid cancer are used. RAI is taken by mouth and collects in any remaining thyroid tissue, including thyroid cancer cells that have spread to other places in the body. Since only thyroid tissue takes up iodine, the RAI destroys thyroid tissue and thyroid cancer cells without harming other tissue. Before a full treatment dose of RAI is given, a small test-dose is given to see if the tumor takes up the iodine.
Surgery is the most common treatment of thyroid cancer. One of the following procedures may be used:
- Lobectomy: Removal of the lobe in which thyroid cancer is found. Biopsies of lymph nodes in the area may be done to see if they contain cancer.
- Near-total thyroidectomy: Removal of all but a very small part of the thyroid.
- Total thyroidectomy: Removal of the whole thyroid.
- Lymphadenectomy: Removal of lymph nodes in the neck that contain cancer.
Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells.
Tyrosine kinase inhibitor therapy is a type of targeted therapy being studied in the treatment of thyroid cancer. Tyrosine kinase inhibitors block signals needed for tumors to grow.
Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances made by glands in the body and circulated in the bloodstream. In the treatment of thyroid cancer, drugs may be given to prevent the body from making thyroid-stimulating hormone (TSH), a hormone that can increase the chance that thyroid cancer will grow or recur.
Also, because thyroid cancer treatment kills thyroid cells, the thyroid is not able to make enough thyroid hormone. Patients are given thyroid hormone replacement pills.