Production of Cu-64 using a solution target

Objectives Cu-64 is currently being utilized in numerous PET imaging studies. The normal practice for Cu-64 production entails the electroplating of isotopically enriched 64Ni onto a gold disk target to enable the 64Ni(p,n)64Cu reaction. In this study a solution target is used for rapid processing as no dissolution of the target material is needed and no modification to the existing infrastructure to handle solid targets are required.

Methods Isotopically enriched Ni-64 powder (>99%, 45 mg) was dissolved in conc. HNO3. The solution was taken to dryness on a rotary evaporator and re-dissolved in 3 mL of 0.01 M HNO3. The solution was irradiated for 120 min at 10 µA. The 64Ni / 64Cu mixture was passed through the CU resin (Eichrom, Lisle, IL) trapping only the Cu-64. The column was washed with 10 mL of 0.001 M HNO3 to remove any last traces of Ni-64. The Cu-64 was eluted using 2 mL of 8 M HCl. To remove the high concentration of HCl, the Cu-64 was trapped on an anion exchange resin (AG 1-X8, Cl- form) and eluted with water.

Results The saturation yield was ~ 4.5 MBq/(μA h) after the CU resin purification. The Ni-64 was efficiently recycled by drying it down on a rotary evaporator and re-dissolving it in 0.01 N HNO3.

Conclusions The study showed the feasibility of cyclotron production of Cu-64 via a solution target.