Rapid synthesis of [18F]FDG without an evaporation step using an ionic liquid

Area of Science:

• Radiochemistry
• Nuclear Medicine
• Organic Synthesis

Background:

• Automated synthesis of 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG) is crucial for clinical applications.
• Traditional synthesis methods often involve multiple steps, including distillation, which can be time-consuming and complex.

Purpose of the Study:

• To develop a novel, simplified synthesis of [18F]FDG that omits the distillation step.
• To optimize fluorination conditions using ionic liquid-containing media for improved efficiency and automation.

Main Methods:

• Fluorination of a precursor using [18F]fluoride in an ionic liquid medium.
• Optimization of base and eluant for effective fluoride elution from anion exchange resin.
• Nucleophilic substitution for 18F-labeling, investigating temperature and reaction medium effects.
• Comparison of liquid-phase and solid-phase alkaline hydrolysis and purification.

Main Results:

• Optimized [18F]fluorination achieved a labeling efficiency of 74.6+/-7.4%.
• Liquid-phase purification yielded 59.1+/-5.1% decay-corrected [18F]FDG with 91.9+/-3.7% radiochemical purity in 13 min.
• Solid-phase purification yielded 48.8+/-6.0% decay-corrected [18F]FDG with 96.0+/-4% radiochemical purity in 19 min.

Conclusions:

• Eliminating evaporation steps through the use of ionic liquids enables a rapid and straightforward [18F]FDG synthesis.
• The developed method is suitable for automated synthesis, improving accessibility of the radiotracer.
• Ionic liquid-mediated fluorination offers a promising alternative for [18F]FDG production.