Cyclotron production of 225 Ac from an electroplated 226 Ra target.

Autor: Nagatsu K; Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan. nagatsu.kotaro@qst.go.jp., Suzuki H; Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan., Fukada M; Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan., Ito T; Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.; Theranostics Research Center, Nihon Medi-Physics, Co., Ltd., Chiba, Japan., Ichinose J; Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.; Theranostics Research Center, Nihon Medi-Physics, Co., Ltd., Chiba, Japan., Honda Y; Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.; Theranostics Research Center, Nihon Medi-Physics, Co., Ltd., Chiba, Japan., Minegishi K; Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan., Higashi T; Department of Molecular Imaging and Theranostics, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan., Zhang MR; Department of Advanced Nuclear Medicine Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.
Jazyk: angličtina
Zdroj: European journal of nuclear medicine and molecular imaging [Eur J Nucl Med Mol Imaging] 2021 Dec; Vol. 49 (1), pp. 279-289. Date of Electronic Publication: 2021 Jul 01.
DOI: 10.1007/s00259-021-05460-7
Abstrakt: Purpose: We demonstrate cyclotron production of high-quality 225 Ac using an electroplated 226 Ra target.
Methods: 226 Ra was extracted from legacy Ra sources using a chelating resin. Subsequent ion-exchange purification gave pure 226 Ra with a certain amount of carrier Ba. The radium target was prepared by electroplating. We successfully deposited about 37 MBq of 226 Ra on a target box. Maximum activation was achieved using 15.6 MeV protons on the target at 20 µA for 5 h. Two functional resins with various concentrations of nitric acid purified 225 Ac and recovered 226 Ra. Cooling the intermediate 225 Ac for 2-3 weeks decayed the major byproduct of 226 Ac and increased the radionuclidic purity of 225 Ac. Repeating the same separation protocol provided high-quality 225 Ac.
Results: We obtained 225 Ac at a yield of about 2.4 MBq at the end of bombardment (EOB), and the subsequent initial purification gave 1.7 MBq of 225 Ac with 226 Ac/ 225 Ac ratio of < 3% at 4 days from EOB. Additional cooling time coupled with the separation procedure (secondary purification) effectively increased the 225 Ac (4n + 1 series) radionuclidic purity up to 99 + %. The recovered 225 Ac had a similar identification to commercially available 225 Ac originating from a 229 Th/ 225 Ac generator.
Conclusion: This procedure, which involves the 226 Ra(p,2n) 225 Ac reaction and the appropriate purification, has the potential to be a major alternative pathway for 225 Ac production because it can be performed in any facility with a compact cyclotron to address the increasing demand for 225 Ac.
(© 2021. The Author(s).)
Databáze: MEDLINE
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