Niobium sputtered Havar foils for the high-power production of reactive [18F]fluoride by proton irradiation of [18O]H2O targets

Niobium sputtered Havar entrance foils were used for the production of reactive [18F]fluoride by proton irradiation of [18O]H2O targets under pressurized conditions. The synthesis yield in the routine production of 2–[18F]fluoro-2-deoxy-glucose (FDG) was used as an indicative parameter of the reactivity of 18F. The yield of FDG obtained with 18F produced in a target with Havar foil was used as a baseline. No statistically significant difference was found in the saturated yields of 18F when using Havar or Havar–Nb sputtered entrance foils. However, the amount of long-lived radionuclidic impurities decreased more than 10-fold using the Havar–Nb entrance foil. The average decay corrected synthesis yield of FDG, evaluated over a period of more than 2 years, was found to be ∼5% higher when using a Havar–Nb entrance foil and a marked improvement on the FDG yield consistency was noted. In addition, the frequency of target rebuilding was greatly diminished when using the Nb sputtered entrance foil.