MedicalTerminology DB

Meaning of irradiation: The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors.

Definition of irradiation

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic irradiation uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called radiation therapy and radiotherapy.

Written and maintained by James Murray Last updated July 21, 2026 Educational reference, not medical advice. Read the limitations.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.