Fully automated synthesis of fluorine-18 PET tracers

Since the development of positron emission tomography (PET) in the 1970s, it has become an increasingly important imaging tool in biology. By detecting positron-emitting radioisotopes, PET can image the biological distribution of labelled drugs or biomolecules, allowing the study of disease and biological pathways. The technique can also determine if drugs reach tissues at effective therapeutic levels.

Carbon-11 and fluorine-18 are the most prevalent isotopes used as PET tracers. Synthetic chemical methods for carbon-11 are well established, but its relatively short half-life of 20 minutes means that radiotracers must be synthesised at the location they are going to be used. Unfortunately not everyone has their own cyclotron! On the other hand, fluorine-18 has a half-life of 110 minutes, which allows synthesised radiotracers to be transported, and permits more complex (ie longer) kinetic studies. Consequently, effective synthetic methods for fluorine-18 are increasingly sought after.