Copper radionuclides for theranostic applications: towards standardisation of their nuclear data. A mini-review

Copper has several clinically relevant radioisotopes and versatile coordination chemistry, allowing attachment of its radionuclides to biological molecules. This characteristic makes it suitable for applications in molecular imaging or radionuclide targeted therapy. Of particular interest in nuclear medicine today is the theranostic approach. This brief review considers five radionuclides of copper. These are Cu-60, Cu-61, Cu-62, Cu-64, and Cu-67. The first four are positron emitters for imaging, and the last one Cu-67 is a β--emitting radionuclide suitable for targeted therapy. The emphasis here is on theory-aided evaluation of available experimental data with a view to establishing standardised cross-section database for production of the relevant radionuclide in high purity. Evaluated cross section data of the positron emitters have been already extensively reported; so here they are only briefly reviewed. More attention is given to the data of the 68Zn(p,2p)67Cu intermediate energy reaction which is rather commonly used for production of 67Cu.

Electrochemical deposition of nickel targets from aqueous electrolytes for medical radioisotope production in accelerators: a review

This paper reviews reported methods of the electrochemical deposition of nickel layers which are used as target materials for accelerator production of medical radioisotopes. The review focuses on the electrodeposition carried out from aqueous electrolytes. It describes the main challenges related to the preparation of suitable Ni target layers, such as work with limited amounts of expensive isotopically enriched nickel; electrodeposition of sufficiently thick, smooth and free of cracks layers; and recovery of unreacted Ni isotopes from the irradiated targets and from used electrolytic baths.

Simple separation of 67Cu from bulk zinc by coprecipitation using hydrogen sulfide gas and silver nitrate

Copper-67 (67Cu), a feasible radionuclide for diagnosis and radiotherapy, is commercially generated from a bulk zinc (Zn) target using the 68Zn(p, 2p)67Cu and 68Zn(γ, p)67Cu nuclear reactions. Because it uses a large amount of zinc, the separation is complex – requiring a combination of three ion exchange columns – and is time-consuming (about 1 day). We developed a quick and easy separation method referred to as “double coprecipitation” using H2S gas and silver nitrate as coprecipitation agents in place of ion exchange columns. We compared this method with a conventional separation method using three ion exchange columns (AG50W-X8, AG1-X8, and Chelex-100) for a natural zinc (natZn) target irradiated by a proton beam. The product quality and the recovery rate with the new method were competitive with the conventional method, and the total operation time was reduced from 1 day to <3 h.