Background
Microfluidic-based radiochemistry has several potential advantages for radiotracer synthesis including accelerated reaction rates, simple purification processes, high yields, high molar activities and one-use disposability/ease of use1. However, despite prompting the interest of the scientific community, few of these systems have been developed as commercially available products1.
Aims
A new microfluidic PET radio-synthesis system performance is underway. [11C]methionine is widely used in clinical PET for imaging tumors and was therefore selected as one of the initial radiotracers for iMiLAB proof-of concept studies2. Here we report the initial results for the synthesis of [11C]methionine.
Methods
[11C]CO2 was produced by the 14N (p, α)11C reaction using 11.5 MeV protons at 5 µA for 1.5 min. [11C]CH3I was produced by the gas phase method and delivered to react with L-homocysteine onto a C18 solid phase matrix embedded in a disposable iMiLAB microfluidic.
Results and Conclusion
The radiotracer was produced within 13 minutes with a radiochemical purity of 99.9 %. Initial [11C]CH3I flow rate studies revealed an increase in radiochemical yield from 31 % to 66 % (decay corrected to end of [11C]CH3I delivery) when the [11C]CH3I flow rate was reduced from 30 to 15 mL/min.
References