TY - JOUR
T1 - Efficient Production of High Specific Activity Thulium-167 at Paul Scherrer Institute and CERN-MEDICIS
AU - Reinhard, Heinke
AU - Chevallay, Eric
AU - Chrysalidis, Katerina
AU - Cocolios, Thomas Elias
AU - Duchemin, Charlotte
AU - Fedosseev, Valentin N.
AU - Hurier, Sophie
AU - Lambert, Laura
AU - Leenders, Benji
AU - Marsh, Bruce A
AU - Sprung, Peter
AU - Stora, Thierry
AU - Tosato, Marianna
AU - Wilkins, Shane
AU - Hui, Zhang
AU - Talip, Zeynep
N1 - Score=10
PY - 2021/10/12
Y1 - 2021/10/12
N2 - 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.
AB - 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.
KW - Medical radionuclides
KW - Thulium-167
KW - Mass separation
KW - Laser resonance ionization
KW - MEDICIS
KW - Auger electrons
KW - ISOL
KW - CERN
KW - PSI
UR - https://ecm.sckcen.be/OTCS/llisapi.dll/open/46065481
U2 - 10.3389/fmed.2021.712374
DO - 10.3389/fmed.2021.712374
M3 - Article
SN - 2296-858X
VL - 8
SP - 1
EP - 17
JO - Frontiers in Medicine
JF - Frontiers in Medicine
M1 - 712374
ER -