A microchip-based technique was developed for the radiolabeling process of positron emission tomography (PET) radiotracers using C–11. Due to C–11’s short half-life (20.4 min) it is beneficial to develop a rapid and efficient synthesis that can be done while the patient is waiting. The investigation began with the non-radioactive synthesis of raclopride ((2S)-(-)-3,5-dichloro-N-((1-ethyl-2-pyrrolidinyl)methyl)-6-hydroxy-2-methoxybenzamide), a compound used to study dopamine receptors. The reaction was optimized on the microchip achieving 2-times the yields using ~1/20th the precursor amounts and ~1/5th the reaction time compared to the conventional method. Consequently, optimal parameters were applied to the radiolabeling synthesis of L-[methyl-11C]-methionine achieving 100% relative activities while the [11C]raclopride synthesis resulted in lower relative activities. Therefore reaction conditions were investigated and a computational mass transfer study showed that the reaction kinetics of the radiolabeling process must be considered for the microchip design.
Copyright is held by the author.
The author granted permission for the file to be printed, but not for the text to be copied and pasted.
Member of collection