If your thyroid cancer comes back (recurs), you may need radiation therapy to the neck. Radiation therapy is used if radioactive iodine has not worked. It may also be used if you are not healthy enough to have surgery, if your cancer could not be entirely removed during surgery, or if your cancer has spread to your bones.

What to think about

The decision to use radiation therapy to treat thyroid cancer that has come back depends on the type of thyroid cancer you have, whether the cancer responds to radioactive iodine, what previous treatments were used, and your general health.

Clinical trials continue to evaluate the best treatments for thyroid cancer. Talk with your doctor about clinical trials in your area. Information about ongoing clinical trials is also available from the National Cancer Institute. For more information, see the Other Places to Get Help section of this topic.