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radiation therapy technologist

ABBR: RT(T). A technologist who assists specialists in nuclear medicine in the proper and safe use of radiation for patient diagnosis and treatment. The roles of the radiation therapy technologist include the operation of radiation detection equipment, the administration of radiopharmaceuticals, and the recognition and early treatment of radiation-related emergencies, among others.

radiation treatment

The administration of high-energy x-ray photons, electrons, or nuclear emissions for the cure of cancer or palliation of symptoms.


(rā′dē-ā″ tor) [LL. radiatus, radiate] A device for radiating heat or light.

infrared r. A device for transmitting infrared rays.


(rad′ĭ-kăl) [L. radicalis, having roots] 1. In chemistry, a group of atoms acting as a single unit, passing without change from one compound to another, but unable to exist in a free state. 2. Pert. to surgery or other therapy to remove or destroy all disease or diseased tissue. SEE: conservative; radical treatment.

acid r. The electronegative portion of a molecule that is left after a positively charged hydrogen is removed.

alcohol r. The portion of an alcohol molecule left when the hydrogen of the hydroxyl [OH-] group is removed.

free r. A molecule containing an odd number of electrons. These molecules contain an open bond or a half bond and are highly reactive. In ischemic injury to tissues (as in myocardial infarction), free radical production may play an important role at certain stages in the progression of the injury.

The body has developed methods of defending against the harmful effects of free radicals. Superoxide dismutases, enzymes in mitochondria, and antioxidants are effective in counteracting the harmful effects of free radicals. SEE: antioxidant; oxidative stress; superoxide; superoxide dismutase.

oxygen r. Hydrogen peroxide (H2O2) or the superoxide radical (O2) produced by the incomplete reduction of oxygen. Oxygen free radicals are released during the respiratory burst phase of phagocytosis by neutrophils and macrophages during inflammation. They cause direct cell damage, increase vascular permeability through damage to the capillary endothelium, and promote chemotaxis. Oxygen free radicals are normally contained by antioxidant protective measures; however, with severe inflammation they cause significant damage. They are believed to be responsible for much of the cellular damage involved in adult respiratory distress syndrome (ARDS), in which massive neutrophil aggregation and phagocytosis occur.

oxygen-derived free r. SEE: oxygen r.; superoxide.

radical treatment

1. An extensive or complete therapy, such as surgical removal of an entire diseased organ and its associated lymphatic drainage. Alternatives to radical treatment may include observation, palliation, modified procedures, lumpectomies, or conservative treatments. 2. Elimination from ...

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