{"id":{"repo_id":"missouri","oai_identifier":"oai:mospace.umsystem.edu:10355/110050"},"canonical_url":"https://search.dev.ndltd.org/etd/missouri/oai:mospace.umsystem.edu:10355/110050","repository":{"repo_id":"missouri","name":"University of Missouri","base_url":"https://mospace.umsystem.edu/oai/request"},"display":{"title":"Production and separation of medically relevant terbium-161 for radiopharmaceutical applications and recycling of target materials","abstract":"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","abstract_html":"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","abstract_has_math":false,"creators":["Bokolo, Patrick Chukwuebuka, Jr."],"institution":"University of Missouri--Columbia","degree_name":"Ph. D.","degree_level":"Doctoral","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":[],"advisors":["Hennkens, Heather"],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025","date_published":"2025","updated_at":"2026-07-24T03:08:32Z","subjects":[],"languages":["eng","English"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.32469/10355/110050"],"render_values":[{"text":"https://doi.org/10.32469/10355/110050","href":"https://doi.org/10.32469/10355/110050","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10355/110050","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Hennkens, Heather"]},{"key":"dc:creator","label":"Author","values":["Bokolo, Patrick Chukwuebuka, Jr."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-01-07T20:07:17Z"]},{"key":"dc:date.issued","label":"Date","values":["2025"]},{"key":"dc:publisher","label":"Institution","values":["University of Missouri--Columbia"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. 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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"]},{"key":"dc:title","label":"Title","values":["Production and separation of medically relevant terbium-161 for radiopharmaceutical applications and recycling of target materials"]}]}],"canonical_facts":{"dc:contributor.advisor":["Hennkens, Heather"],"dc:creator":["Bokolo, Patrick Chukwuebuka, Jr."],"dc:date.accessioned":["2026-01-07T20:07:17Z"],"dc:date.issued":["2025"],"dc:description.abstract":["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"],"dc:identifier.doi":["https://doi.org/10.32469/10355/110050"],"dc:identifier.uri":["https://hdl.handle.net/10355/110050"],"dc:language":["English"],"dc:language.iso":["eng"],"dc:publisher":["University of Missouri--Columbia"],"dc:title":["Production and separation of medically relevant terbium-161 for radiopharmaceutical applications and recycling of target materials"],"dc:type":["Thesis"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["University of Missouri--Columbia"]},"updated_at":"2026-07-24T03:08:32Z"}