Medical Applications of Radioisotopes

Abstract

David Kuhl has said that there are only two insights that we can have into nature, namely "what things are made of, and how they work". Despite the contemporary explosive growth in our ability to image the body, a growth that is driven by the computer, radionuclide diagnosis is , with the possible exception of NMR, the only method that examines function and not structure. The applications of radionuclides in medicine can be classified as: a) In vitro tests; b) In vivo tests: imaging, non-imaging; c) Uses in treatment. In vitro uses are important but use very small activities and are in part being replaced by such alternative methods as enzymatic assays. The major uses of radionuclides in medicine are in in vivo diagnosis: these uses are those in which small amounts of radiotracer, usually between 75 and 750 megabecquerels, are administered to patients and the activity either measured or imaged. Lastly there are a few therapeutic uses of injected radionuclides although such uses may involve activities of us to 6000 megabecquerels each.