Optimisation of [¹¹C]-choline synthesis

Area of Science:

• Radiochemistry
• Nuclear Medicine
• Green Chemistry

Background:

• [¹¹C]-choline is a vital PET/CT imaging agent.
• Production challenges include short radionuclide half-lives and residual solvent (DMF).
• Eliminating DMF is crucial for improving synthesis quality.

Purpose of the Study:

• To compare green chemistry (ethanol) and dry synthesis methods for [¹¹C]-choline production.
• To evaluate DMF elimination and overall synthesis efficiency.
• To optimize [¹¹C]-choline synthesis for PET/CT applications.

Main Methods:

• Comparison of green chemistry (ethanol solvent) and dry synthesis against a DMF-based method.
• Solid-phase synthesis optimization for DMF elimination and yield.
• Quality control testing for residual solvents and precursor levels.

Main Results:

• Solid-phase synthesis effectively eliminated DMF, achieving the highest final release.
• Optimized synthesis yielded 65% ±3% radiochemical yield in 12 minutes.
• Achieved a 27% increase in saturation yield, resulting in 9 GBq higher activity.
• Residual DMEA levels met Pharmacopoeia monograph limits.

Conclusions:

• Solid-phase synthesis is the most effective method for producing high-purity [¹¹C]-choline.
• This approach addresses DMF contamination and improves synthesis efficiency.
• Optimized synthesis provides a reliable and high-yield method for this important PET/CT radiotracer.