Half-life: 68 minutes
Main emission lines: 511 keV annihilation line
Gallium-68 is a widely used radioisotope in positron emission tomography (PET) and it has a half-life of 68 minutes. This isotope can be used to label different small molecules and peptides for diverse applications.The most popular applications are for prostate cancer imaging and for neuroendocrine tumours.
A germanium-68/gallium-68 generator is a device used to extract the positron-emitting isotope Gallium-68 of Gallium from a source of decaying germanium-68. The parent isotope germanium-68 has a half-life of 271 days and can be easily utilized for in-hospital production of generator produced Gallium-68. Its decay product gallium-68 (with a half-life of only 68 minutes, inconvenient for transport) is extracted and used for certain positron emission tomography nuclear medicine diagnostic procedures, where the radioisotope's relatively short half-life and emission of positrons for creation of 3-dimensional PET scans, are useful.
Gallium emits an annihilation line similar to Fluorine-18. These two isotopes can only be distinguished by evaluating their half-lives: Fluorine-18 has a half-life of 109 minutes, compared to 68 minutes for Gallium.