Radiation Therapy for Thyroid Cancer

If radiation is part of your thyroid cancer treatment, you will work closely with the radiation oncologist to determine the best plan for you.

There are two ways you can have radiation therapy for thyroid cancer.

One way is to treat the cancer from the inside. You take a capsule of radioactive iodine (I-131). Once you swallow the capsule, the cancer cells pick up the iodine, which kills them. This treatment affects thyroid cancer cells but has very little effect on healthy cells. It takes eight to 12 weeks for your thyroid to become normal after treatment.

The second way to treat thyroid cancer with radiation is external beam radiation therapy. Radiation therapy uses high-energy radiation beams that penetrate deep into the body to safely and effectively treat cancer and other diseases. This treatment can also be used to relieve symptoms, such as pain caused by cancer.

Radiation works by damaging cancer cells so that they cannot reproduce and eventually die. When cancer cells die, the body removes them naturally over time. Your body’s healthy cells are also sensitive to radiation. However, normal cells can repair radiation damage, while cancer cells cannot.