Production and separation of medically relevant terbium-161 for radiopharmaceutical applications and recycling of target materials

The development of effective production and purification methods for terbium-161 (161Tb) is crucial for advancing targeted radionuclide therapy applications in nuclear medicine. Here, we present two approaches for the production and purification of 161Tb using high-flux neutron irradiation and multi-step chromatographic separation. Enriched [160Gd]Gd(NO3)3 and [160Gd]Gd2O3 targets (98.2-99.96% isotopic enrichment) were irradiated at the University of Missouri Research Reactor (MURR) at thermal neutron fluxes of 1.76 × 1014 - 3.30 × 1014 n·cm-2·sec-1, producing 161Tb at the end of irradiation. For research-scale production, a cation-exchange HPLC method followed by sequential LN and RE/PF resin columns achieved overall recovery yields of 55 ± 7%. For larger-scale processing, an extraction chromatography method using TK212, TK211, TK221, and A-8 resins was implemented, enabling purification from targets containing up to 201 mg Gd with recovery yields of 89 ± 4%. Both methods produced 161Tb with high radiochemical (>99%) and radionuclidic (>99.9%) purity. The extraction chromatography method demonstrated superior radiolabeling performance, achieving maximum apparent molar activities of 1300 µCi/nmol for DOTA at 3.5 µCi/µL concentration, reaching up to 143,000 µCi/nmol at higher activity concentrations, and 200-400 µCi/nmol for DOTA-TATE at 7 µCi/µL concentration. An efficient target recycling method was implemented, achieving >96% recovery of the Gd. These complementary methods establish reliable approaches for both research and potential clinical scale 161Tb production while addressing key considerations for future applications

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Chemistry

Grantor dc:publisher

University of Missouri--Columbia

Year dc:date.issued

2025

Author dc:creator

• Bokolo, Patrick Chukwuebuka, Jr.

Advisor dc:contributor.advisor

• Hennkens, Heather

Language dc:language.iso

eng, English

DOI

https://doi.org/10.32469/10355/110050

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/110050