NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,847 terms related to cancer and medicine.
Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related word or phrase in the search box.
- external radiation therapy
- listen (...RAY-dee-AY-shun THAYR-uh-pee)
A type of radiation therapy that uses a machine to aim high-energy rays at the cancer from outside of the body. Also called external-beam radiation therapy.