irradiation

(ih-RAY-dee-AY-shun) 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.

The amount of radiant energy from a selected source that falls on a surface in a given amount of time.

Illumination with electromagnetic radiation, typically of sufficiently high energy (low-wavelength UV or gamma, etc.) to disrupt biological macromolecules and hence induce mutations.

The product of irradiance and time, i.e., the time integral of irradiance. Note: For example, an irradiation of 100 J/m² (joules per square meter) is obtained when an irradiance of 25 W/m² (watts per square meter) is continuously incident for 4 seconds.