Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama.
Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri.
J Nucl Med. 2021 Jan;62(1):131-136. doi: 10.2967/jnumed.120.242941. Epub 2020 Jul 3.
Theranostic strategies involve select radionuclides that allow diagnostic imaging and tailored radionuclide therapy in the same patient. An example of a Food and Drug Administration-approved theranostic pair is the Ga- and Lu-labeled DOTATATE peptides, which are used to image neuroendocrine tumors, predict treatment response, and treat disease. However, when using radionuclides of 2 different elements, differences in the pharmacokinetic and pharmacodynamic profile of the agent can occur. Theranostic agents that incorporate the matched-pair radionuclides of scandium-Sc/Sc or Sc/Sc-would guarantee identical chemistries and pharmacologic profiles. The aim of this study was to investigate production of Sc via proton-induced nuclear reactions on titanium nuclei using a 24-MeV cyclotron. Aluminum, niobium, and tantalum target holders were used with titanium foils and pressed TiO to produce scandium radionuclides with proton energies of up to 24 MeV. Irradiated targets were digested using NHHF and HCl in a closed perfluoroalkoxy alkane vessel in 90 min. Scandium radionuclides were purified via ion-exchange chromatography using branched -tetra-2-ethylhexyldiglycolamide. The titanium target material was recovered via alkali precipitation with ammonia solution. Titanium foil and TiO were digested with an average efficiency of 98% ± 3% and 95% ± 1%, respectively. The typical digestion time was 45 min for titanium foil and 75 min for TiO The average scandium recovery was 94% ± 3%, and the average titanium recoveries from digested titanium foil and TiO after precipitation as TiO were 108% ± 8% and 104% ± 5% of initial mass, respectively. This work demonstrated a robust method for the cyclotron production of scandium radionuclides that could be used with natural or enriched TiO target material.
治疗策略涉及选择允许在同一患者中进行诊断成像和定制放射性核素治疗的放射性核素。一种经美国食品和药物管理局批准的治疗策略是 Ga 和 Lu 标记的 DOTATATE 肽，它用于成像神经内分泌肿瘤，预测治疗反应并治疗疾病。然而，当使用两种不同元素的放射性核素时，会出现药物的药代动力学和药效学特征的差异。包含匹配对放射性核素钪 - Sc/Sc 或 Sc/Sc 的治疗剂将保证相同的化学和药理特征。本研究旨在使用 24-MeV 回旋加速器研究通过质子诱导钛核核反应产生 Sc。 使用铝、铌和钽靶架以及钛箔和压制 TiO ，以 24 MeV 的质子能量产生钪放射性核素。用 NH 4 HF 和 HCl 在封闭的全氟烷氧基烷烃容器中在 90 分钟内消化辐照的靶标。使用分支 - 四-2-乙基己基二甘醇酰胺通过离子交换色谱法纯化钪放射性核素。用氨溶液通过碱沉淀回收钛靶材料。钛箔和 TiO 的平均消化效率分别为 98% ± 3%和 95% ± 1%。典型的消化时间分别为 45 分钟用于钛箔和 75 分钟用于 TiO 。平均钪回收率为 94% ± 3%，消化后的钛箔和 TiO 沉淀为 TiO 后钛的平均回收率分别为初始质量的 108% ± 8%和 104% ± 5%。这项工作展示了一种用于回旋加速器生产钪放射性核素的强大方法，可与天然或富集的 TiO 靶材料一起使用。
