Recent Progress in Radiofluorination of Peptides for PET Molecular Imaging

Because of its low positron energy, lack of side emission, and a moderate half-life, Fluorine-18 (β+, 0.635 MeV [97%], t1/2 = 109.8 min) has ideal physical properties for positron emission tomography (PET). With the increasing numbers of peptides that are potentially applicable for molecular imaging of diseases, novel and simple 18F-labeling methods have been actively investigated and reported. In this review, a few well established and widely-used radiofluorination strategies are discussed. Novel approaches including click chemistry, one-step chelation labeling (i.e. Al18F-NOTA), and silicon-based 18F labeling are described as well.