A radionuclide generator is a device which provides a local supply of a short-lived
radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...
substance from the decay of a longer-lived parent
radionuclide
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transfer ...
. They are commonly used in
nuclear medicine
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is " radiology done inside out" because it records radiation emi ...
to supply a
radiopharmacy
Nuclear pharmacy, also known as radiopharmacy, involves preparation of radioactive materials for patient administration that will be used to diagnose and treat specific diseases in nuclear medicine. It generally involves the practice of combining ...
. The generator provides a way to separate the desired product from the parent, typically in a process that can be repeated several times over the life of the parent.
Use of a generator avoids the challenge of distributing short-lived radionuclides from the original production site (typically a
nuclear reactor
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat fr ...
) to individual users; the loss of
activity due to decay in transit can result in too little being supplied or the need for much larger initial quantities to be sent out (incurring additional production and transport costs). An alternative to generators for on-site production of radionuclides is a
cyclotron
A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. Lawrence, Ernest O. ''Method and apparatus for the acceleration of ions'', filed: Jan ...
, though it is uncommon that the same radionuclide can be provided by both methods. It is feasible to have cyclotrons at larger centres, but they are much more expensive and complex than generators. In some cases a cyclotron is used to produce the parent radionuclide for a generator.
Long-lived radionuclides which are administered to a patient with a view to utilising useful properties of a daughter product have been termed
in-vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and pl ...
generators, though they are not routinely used clinically.
Commercial and experimental generators
Further reading
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References
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Nuclear medicine