Efficient Production of High Specific Activity Thulium-167 at Paul Scherrer Institute and CERN-MEDICIS

Frontiers in Medicine

Peter Sprung¹  Marianna Tosato²  Zeynep Talip²  Hui Zhang³  Bruce A. Marsh⁴  Thierry Stora⁴  Eric Chevallay⁴  Valentin N. Fedosseev⁴  Shane G. Wilkins⁴  Katerina Chrysalidis⁴  Laura Lambert⁴  Thomas E. Cocolios⁵  Sophie Hurier⁶  Benji Leenders⁷  Charlotte Duchemin⁸  Reinhard Heinke⁸  Nicholas P. van der Meulen⁹ 

[1] Analytic Radioactive Materials, Paul Scherrer Institute, Villigen, Switzerland;Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen, Switzerland;Division Large Research Facilities, Paul Scherrer Institute, Villigen, Switzerland;European Organization for Nuclear Research CERN, Geneva, Switzerland;Institute for Nuclear and Radiation Physics, KU Leuven, Leuven, Belgium;Institute for Nuclear and Radiation Physics, KU Leuven, Leuven, Belgium;Belgian Nuclear Research Centre SCK CEN, Mol, Belgium;Institute for Nuclear and Radiation Physics, KU Leuven, Leuven, Belgium;Belgian Nuclear Research Centre SCK CEN, Mol, Belgium;Department of Electromechanical, Systems and Metal Engineering, Ghent University, Ghent, Belgium;Institute for Nuclear and Radiation Physics, KU Leuven, Leuven, Belgium;European Organization for Nuclear Research CERN, Geneva, Switzerland;Laboratory of Radiochemistry, Paul Scherrer Institute, Villigen, Switzerland;Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen, Switzerland;

关键词: medical radionuclides;    thulium-167;    mass separation;    laser resonance ionization;    MEDICIS;    Auger electrons;   

DOI  :  10.3389/fmed.2021.712374

来源: Frontiers

【 摘 要 】

Thulium-167 is a promising radionuclide for nuclear medicine applications with potential use for both diagnosis and therapy (“theragnostics”) in disseminated tumor cells and small metastases, due to suitable gamma-line as well as conversion/Auger electron energies. However, adequate delivery methods are yet to be developed and accompanying radiobiological effects to be investigated, demanding the availability of 167Tm in appropriate activities and quality. We report herein on the production of radionuclidically pure 167Tm from proton-irradiated natural erbium oxide targets at a cyclotron and subsequent ion beam mass separation at the CERN-MEDICIS facility, with a particular focus on the process efficiency. Development of the mass separation process with studies on stable 169Tm yielded 65 and 60% for pure and erbium-excess samples. An enhancement factor of thulium ion beam over that of erbium of up to several 104 was shown by utilizing laser resonance ionization and exploiting differences in their vapor pressures. Three 167Tm samples produced at the IP2 irradiation station, receiving 22.8 MeV protons from Injector II at Paul Scherrer Institute (PSI), were mass separated with collected radionuclide efficiencies between 11 and 20%. Ion beam sputtering from the collection foils was identified as a limiting factor. In-situ gamma-measurements showed that up to 45% separation efficiency could be fully collected if these limits are overcome. Comparative analyses show possible neighboring mass suppression factors of more than 1,000, and overall 167Tm/Er purity increase in the same range. Both the actual achieved collection and separation efficiencies present the highest values for the mass separation of external radionuclide sources at MEDICIS to date.

【 授权许可】

CC BY