Comparative Study with 89Y-foil and 89Y-pressed Targets for the Production of 89Zr

Zirconium-89 (Zr-89, t(1/2) = 3.27 days) owns great potential in nuclear medicine, being extensively used in the labelling of antibodies and nanoparticules. Zr-89 can be produced by cyclotron via an Y-89(p,n)Zr-89 reaction while using an Y-89-foil target. In this study, we investigated for the first time the use of Y-89-pressed target for the preparation of Zr-89-oxalate via a (p,n) reaction. We performed comparative studies with an Y-89-foil target mounted on custom-made target supports. A new automated cassette-based purification module was used to facilitate the purification and the fractionation of Zr-89-oxalate. The effective molar activity (EMA) was calculated for both approaches via titration with deferoxamine (DFO). The radionuclidic purity was determined by gamma-ray spectroscopy and the metal impurities were quantified by ICP-MS on the resulting Zr-89-oxalate solution. The cassette-based purification process leading to fractionation is simple, efficient, and provides very high EMA of Zr-89-oxalate. The total recovered activity was 81 +/- 4% for both approaches. The highest EMA was found at 13.3 MeV and 25 A for 0.25-mm thick Y-89-foil. Similar and optimal production yields were obtained at 15 MeV and 40 A while using 0.50-mm thick Y-89-foil and pressed targets. Metallic impurities concentration was below the general limit of 10 ppm for heavy metals in the US and Ph.Eur for both Y-89-foil and pressed targets. Overall, these results show that the irradiation of Y-89-pressed targets is a very effective process, offering an alternative method for Zr-89 production.