Comparative study with 89Y-foil and 89Y-pressed targets for the production of 89Zr

Abstract

Zirconium-89 (89Zr, t1/2 = 3.27 days) owns great potential in nuclear medicine, being extensively used in the labelling of antibodies and nanoparticules. 89Zr can be produced by cyclotron via an 89Y(p,n)89Zr reaction while using an 89Y-foil target. In this study, we investigated for the first time the use of 89Y-pressed target for the preparation of 89Zr-oxalate via a (p,n) reaction. We performed comparative studies with an 89Y-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 89Zr-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 89Zr-oxalate solution. The cassette-based purification process leading to fractionation is simple, efficient, and provides very high EMA of 89Zr-oxalate. The total recovered activity was 81 ± 4% for both approaches. The highest EMA was found at 13.3 MeV and 25 μA for 0.25-mm thick 89Y-foil. Similar and optimal production yields were obtained at 15 MeV and 40 μA while using 0.50-mm thick 89Y-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 89Y-foil and pressed targets. Overall, these results show that the irradiation of 89Y-pressed targets is a very effective process, offering an alternative method for 89Zr production.