Radiation therapy

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. External radiation therapy uses a machine outside the body to send radiation toward the area of the body with cancer. Intensity-modulated radiation therapy (IMRT) is a type of 3-dimensional (3-D) external radiation therapy that uses a computer to make pictures of the size and shape of the tumor. Thin beams of radiation of different intensities (strengths) are aimed at the tumor from many angles. This type of radiation therapy is less likely to cause dry mouth, trouble swallowing, and damage to the skin.

Radiation therapy to the neck may change the way the thyroid gland works. Blood tests may be done to check the thyroid hormone level in the body before treatment and at regular checkups after treatment.