Tantalum [ 18O]Water Target for the Production of [ 18F]Fluoride with High Reactivity for the Preparation of 2-Deoxy-2-[ 18F]Fluoro-D-Glucose

Abstract

Purpose: To develop a new tantalum [ 18O]water target for the routine production of reactive, no-carrier-added [ 18F]fluoride ion in Curie amounts for the synthesis of radiopharmaceuticals. Procedures: The tantalum target body was filled with 0.86 mL of 95% enriched [ 18O]water and irradiated with 10.2 MeV protons on target with beam currents of 26–40 μA for 60–90 min. [ 18F]Fluoride ion produced is trapped in an anion exchange resin cartridge and the expensive [ 18O]water is recovered for recycling. The [ 18F]fluoride ion is released from the resin by elution with a dilute solution of K 2CO 3 and utilized in the synthesis of 2-deoxy-2-[ 18F]fluoro-D-glucose (FDG). Results: Using the tantalum target, Curie levels of no-carrier-added [ 18F]fluoride ion (specific activity: >30,000 Ci/mmol) were reliably and reproducibly produced ( n > 100), from which FDG was synthesized in 70% radiochemical yield. Conclusion: Tantalum [ 18O]water target body for the production of [ 18F]fluoride ion has the best characteristics from the standpoint of [ 18F]fluoride ion recovery and its radiochemical reactivity and low induced activation. This new target has the potential to replace the currently used silver and titanium [ 18O]targets for the routine production of [ 18F]fluoride ion. (Mol Imag Biol 2002;4:65–70)