High-efficiency [¹⁸F]fluoride pre-concentration using a laser-micromachined anion-exchange micro-cartridge

Area of Science:

• Radiochemistry
• Nuclear Medicine
• Microfluidics

Background:

• Positron Emission Tomography (PET) relies heavily on fluorine-18 radiopharmaceuticals.
• Traditional synthesis methods involve time-consuming steps like azeotropic drying, leading to activity loss.
• Microfluidic devices offer potential for improved efficiency and reduced reagent use.

Purpose of the Study:

• To develop a novel micro-cartridge for efficient trapping and elution of fluorine-18.
• To integrate microfluidic technology into conventional radiopharmaceutical synthesis workflows.

Main Methods:

• Fabrication of a borosilicate glass micro-cartridge using ultrashort laser pulse machining.
• Evaluation of trapping and recovery efficiency of the micro-cartridge for [18F]fluoride.
• Application of the micro-cartridge in the radiosynthesis of [18F]fluoromisonidazole ([18F]FMISO).

Main Results:

• The micro-cartridge demonstrated high trapping and recovery efficiency (94.09 ± 0.12%) for [18F]fluoride, exceeding 123 GBq.
• Elution was achieved using a minimal volume of acetonitrile solution with Kryptofix 2.2.2 and K2CO3.
• 100% radiochemical conversion to THP-protected [18F]FMISO was obtained within 10 minutes at 110°C.

Conclusions:

• The developed micro-cartridge is an effective tool for [18F]fluoride handling.
• It facilitates the integration of microfluidic systems into existing radiopharmaceutical preparation cassettes.
• This innovation leads to more efficient and potentially faster radiopharmaceutical synthesis.