Fully automated [18F]fluorocholine synthesis in the TracerLab MX FDG Coincidence synthesizer.

We developed a new fully automated method for the radiosynthesis of [18F]fluorocholine by modifying the commercial 2-[18F]fluoro-2-d-deoxy-glucose ([18F]FDG) synthesizer module (GE TracerLab MX, formerly Coincidence). [18F]Flurocholine was synthesized by (18)F-fluoroalkylation of N,N-dimethylaminoethanol using [18F]fluorobromomethane as fluoromethylating agent. [18F]Fluorobromomethane was produced by reaction of dibromomethane with [18F]fluoride, assisted by Kryptofix 2.2.2. After purification on solid-phase extraction cartridges, the [18F]fluorocholine was obtained in 15-25% radiochemical yields (decay not corrected), with more than 99% radiochemical purity. Specific activity was more than 37 GBq/micromol. Synthesis time was less than 35 min. This new automated synthesis technique provides high and reproducible yields that could be dedicated for routine use with the same [18F]FDG disposable cassette system.