Production of Mass-Separated Erbium-169 Towards the First Preclinical in vitro Investigations
Zeynep Talip, Francesca Borgna, Cristina Müller, J. Ulrich, Charlotte Duchemin, J.P. Ramos, Thierry Storà, U. Köster, Youcef Nedjadi, Vadim Gadelshin, V. N. Fedosseev, F. Juget, Claude Bailat, Adelheid Fankhauser, S. G. Wilkins, Laura Lambert, B. A. Marsh, Д. В. Федоров, E. Chevallay, P. Fernier, Roger Schibli, Nicholas P. van der Meulen
Abstract
The β − -particle-emitting erbium-169 is a potential radionuclide toward therapy of metastasized cancer diseases. It can be produced in nuclear research reactors, irradiating isotopically-enriched 168 Er 2 O 3 . This path, however, is not suitable for receptor-targeted radionuclide therapy, where high specific molar activities are required. In this study, an electromagnetic isotope separation technique was applied after neutron irradiation to boost the specific activity by separating 169 Er from 168 Er targets. The separation efficiency increased up to 0.5% using resonant laser ionization. A subsequent chemical purification process was developed as well as activity standardization of the radionuclidically pure 169 Er. The quality of the 169 Er product permitted radiolabeling and pre-clinical studies. A preliminary in vitro experiment was accomplished, using a 169 Er-PSMA-617, to show the potential of 169 Er to reduce tumor cell viability.