Cingoranelli Shelbie Jaylene, Putnam Emily E, Appiah Jean Pierre, Rider Jason, Burnett Logan, Lapi Suzanne E
Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave. S., Birmingham, AL, 35294, USA.
Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, 35233, USA.
EJNMMI Radiopharm Chem. 2024 Dec 18;9(1):89. doi: 10.1186/s41181-024-00321-8.
Scandium-47 is the therapeutic counterpart to the diagnostic radionuclides, Sc and Sc. Together, these form elementally matched theranostic nuclide pairs, but their incorporation into radiopharmaceuticals requires developing production techniques leading to radioscandium isotopes with high chemical and radionuclidic purity. Previous Sc production methods involved expensive, enriched titanium targets that require additional procedures for target recovery. This work investigates the irradiation of natural vanadium targets and the development of purification methods for high-purity Sc. Natural vanadium foils were used in cyclotron target configurations. Targets were irradiated with 24 MeV protons at currents of up to 80 µA. A purification method was developed by determining the K values of Sc, Cr, and V using MP-50 resin. The final purification method used MP-50 and CM resin columns to isolate the Sc from V and co-produced Cr. Inductively Coupled Plasma Mass Spectrometry (ICP-MS), gamma-ray spectroscopy, and a DOTA titration were used to characterize the Sc product.
Two cyclotron targets were designed, a small-scale target for developing a purification procedure and a high-power target for scaled-up production. The high-power target maximum current was 80 µA of 24 MeV protons. The yield for an 8 h irradiation at 80 µA of 24 MeV protons, was 128.02 ± 11.1 MBq of Sc at End of Bombardment. The radionuclidic purity of Sc was 99.5 ± 0.2%. The purification using MP-50 and CM columns resulted in the removal of V target and Cr contaminate in the final Sc product, with an average recovery of 72 ± 2.1% and a DOTA apparent molar activity of 7733 ± 155 MBq/µmol. ICP-MS results showed that all top-row transition metals were below the limit of detection (< 1 ppb) with the exception of Zn, which was 64.6 ± 10.3 ppb.
A high-power cyclotron target capable of withstanding a proton current of 80 µA was developed. A novel separation method was developed for isolating the Sc from the vanadium target and the co-produced Cr contaminate. The final product characterization resulted in a chemically and radionuclidically pure Sc product with high recovery yields.
钪-47是诊断性放射性核素钪和钪的治疗对应物。它们共同构成了元素匹配的治疗诊断核素对，但将它们纳入放射性药物需要开发生产技术，以生产出具有高化学纯度和放射性核纯度的放射性钪同位素。以前的钪生产方法涉及昂贵的富集钛靶，需要额外的靶回收程序。这项工作研究了天然钒靶的辐照以及高纯度钪的纯化方法的开发。天然钒箔用于回旋加速器靶配置。用高达80 μA的电流的24 MeV质子辐照靶。通过使用MP-50树脂测定钪、铬和钒的K值，开发了一种纯化方法。最终的纯化方法使用MP-50和CM树脂柱从钒和共产生的铬中分离出钪。使用电感耦合等离子体质谱（ICP-MS）、伽马射线光谱和DOTA滴定来表征钪产物。
设计了两个回旋加速器靶，一个用于开发纯化程序的小规模靶和一个用于扩大生产的高功率靶。高功率靶的最大电流为80 μA的24 MeV质子。在轰击结束时，以80 μA的24 MeV质子进行8小时辐照的产率为128.02±11.1 MBq的钪。钪的放射性核纯度为99.5±0.2%。使用MP-50和CM柱进行纯化，最终的钪产物中钒靶和铬污染物被去除，平均回收率为72±2.1%，DOTA表观摩尔活度为7733±155 MBq/μmol。ICP-MS结果表明，除锌（64.6±10.3 ppb）外，所有第一排过渡金属均低于检测限（<1 ppb）。
开发了一种能够承受80 μA质子电流的高功率回旋加速器靶。开发了一种新颖的分离方法，用于从钒靶和共产生的铬污染物中分离出钪。最终产物表征得到了一种化学和放射性核纯度高、回收率高的钪产物。
