Non-HPLC methods for the production of 18F, 11C and 68Ga PET tracers

Full text: The most popular PET radionuclides in routine clinical use are 11C and 18F, although other radionuclides, such as 68Ga, continue to make headlines. This is due to their well established chemistry, their utility for labeling low molecular weight compounds, and their ease of production in modern PET cyclotrons or via commercially available generators. Their relatively short half lives, along with the global trend toward Good Manufacturing Practice in PET drug production has necessitated the development of aseptic, robust and rapid labeling methodologies. This is achieved by the use of automated radiochemistry systems, which, in turn, has allowed radiosynthesis scale-up and multiple dose preparation. Major impediments to routine production of a number of useful 11C, 18F and 68Ga PET tracers, and to new tracer development, remain: 1) the necessity of thorough system clean up in between consecutive runs; and 2) inconsistent yields and prolonged synthesis time when using HPLC methods for final product separation and purification. To address these issues, new radiochemistry applications have been developed for the radiochemistry modules: a) for 18F: FLT Lite, F-MISO Lite, F-Choline Lite, and FET Lite; b) for 11C: Acetate, Methyl Iodide, Methionine, Choline; c) for 68Ga: DOTA-Peptides. These methods utilize sterile disposable kits, and allow for the PET tracers to be purified and isolated with SPE cartridges only, thus eliminating the need for HPLC separation. The processes and the radiochemical yields obtained with these methods will be presented, and their utility discussed