Radionuclide generators for nuclear medicine

Quantitative studies of rapid and dynamic physiological processes can be obtained by positron emission tomography (PET) and possibly by single-photon emission computed tomography (SPECT). These studies require a high flux of photons from short-lived radionuclides to provide adequate statistical sampling with minimum radiation dose to the patient. Generators provide short-lived radionuclides that are easily separated from long-lived parent radionuclides adsorbed to an ion exchange column. The daughter radionuclides are eluted with physiological eluent solution. Generators for PET and SECT are listed. The short half-life of the radionuclides permits intravenous injections of 10 to 100 mCi and serial studies can be performed every 5 to 30 min. The longer lived 68-min 68Ga for PET and 6-h /sup 99m/Tc for SPECT prohibits their use for serial studies; however, their half-lives permit radiolabeling of lipophilic complexes and biochemical substrates