Automated synthesis of [18F](2S,4R)-4-fluoroglutamine on a GE TRACERlab™ FX-N Pro module

• The radiosynthesis of [18F]fluoroglutamine was optimized with improved yield and purity.
• Fully automated synthesis was established on a GE TRACERlab™ FX-N Pro module.
• Radiochemical yield of 21±3% (uncorrected, n=5) was obtained with good reproducibility.
• The automation could be easily adapted to cGMP production for routine clinical use.

Glutamine (Gln) and its analogues may serve as imaging agents for tumor diagnosis using positron emission tomography (PET), especially for tumors with negative [18F]FDG scan. We report the first automated synthesis of [18F](2S,4R)-4-fluoroglutamine ([18F]FGln) on a GE TRACERlab™ FX-N Pro module. [18F]FGln was obtained in 80±3 min with a radiochemical yield of 21±3% (n=5, uncorrected). The radiochemical purity was >98%, and optical purity 90±5%. The synthesis is highly reproducible with good chemical purity, radiochemical yield, and is suitable for translation to cGMP production.