Synthesis of oncological [11C]radiopharmaceuticals for clinical PET

Positron emission tomography (PET) is a nuclear medicine modality which provides quantitative images of biological processes in vivo at the molecular level. Several PET radiopharmaceuticals labeled with short-lived isotopes such as 18F and 11C were developed in order to trace specific cellular and molecular pathways with the aim of enhancing clinical applications. Among these [11C]radiopharmaceuticals are N-[11C]methyl-choline ([11C]choline), l-(S-methyl-[11C])methionine ([11C]methionine) and 1-[11C]acetate ([11C]acetate), which have gained an important role in oncology where the application of 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG) is suboptimal. Nevertheless, the production of these radiopharmaceuticals did not reach the same level of standardization as for [18F]FDG synthesis. This review describes the most recent developments in the synthesis of the above-mentioned [11C]radiopharmaceuticals aiming to increase the availability and hence the use of [11C]choline, [11C]methionine and [11C]acetate in clinical practice.