Radiation Terms

back arrow       forward arrow

  • Brachytherapy

    means radiation that is being emitted in close proximity to or inside the cancer tumor. It is also referred to as "implant therapy".

  • Half-life

    the time in which one half of the atoms of a particular radioactive substance disintegrates into another nuclear form. Half-lives vary from millionths of a second to billions of years.

  • Implant therapy

    small radioactive seeds are implanted in or near the cancer lesions. Seeds may be implanted permanently or temporarily depending on the type of cancer being treated.

  • mrem

    unit of radiation dose. It is the product of the absorbed dose (i.e., the amount of energy imparted in the body) and a quality factor for the type of ionizing radiation being measured.

  • Radiation

    particles or photons emitted from the nucleus of unstable radioactive atoms as a result of radioactive decay Also, it refers to x-rays emitted by an x-ray machine.

  • Radioactive contamination

    deposition of radioactive material in any place where it could potentially be harmful to individuals.

  • Radioactive decay

    decrease in the amount of any radioactive material with the passage of time due to the spontaneous emission of radiation from an atomic nucleus.

  • Radioisotope

    an unstable isotope of an element that decays or disintegrates spontaneously, emitting radiation.

  • Radiopharmaceutical therapy (capsule or liquid therapy)

    Patients who have had their thyroid removed because of cancer typically undergo this treatment. Radioactive I-131 capsules or liquid is administered to a patient orally. The I-131 enters the bloodstream and is "taken up" by any remaining thyroid cancer cells. The radiation from the I-131 will destroy these remaining cancer cells. Another type of treatment is radiolabeled antibody therapy. Patients undergoing treatment for lymphoma or leukemia are administered I-131 labeled antibodies intravenously, and will remain in radiation isolation for a much longer period of time than the thyroid cancer patients Remaining I-131 is eliminated via the urine, feces and other bodily fluids.

  • Seeds

    small metal sources containing radioactive material. Seeds are made of radioactive material which is sealed and doubly encapsulated in metal.

SEE ALSO Radiation Safety Manual Glossary

back arrow       forward arrow