Advances in processes for PET radiotracer synthesis: separation of [¹⁸F]fluoride from enriched [¹⁸O]water

Positron emission tomography (PET) is a powerful scientific and clinical tool for the study and visualization of human physiology that can provide important information about metabolism and diseases such as cancer. At present, [(18)F]fluorodeoxyglucose ([(18)F]FDG) is the most frequently used radiotracer for the routine clinical evaluation of malignant tumors in a range of body tissues. FDG synthesis is continuously being developed to improve and simplify the synthetic procedure including the isolation of [(18)F]fluoride from [(18)O]water. There are many methods reported in literature for the isolation of [(18)F]fluoride, including evaporation, coat-capture-elution, the use of cation-exchange resin and electrode trapping. This review article gives an overview of some of the most common methods for the separation of [(18)F]fluoride ions from [(18)O]water, highlighting the potential strength of the methods and also problems and weaknesses for synthesis of (18)F PET tracers.