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内容記述 |
Astatine-211 (²¹¹At) is a promising radionuclide for targeted alpha therapy (TAT), as it can be produced using a cyclotron and bismuth, an inexpensive and readily available target material. However, its clinical application will be constrained by its relatively short half-life of 7.2 hours. To promote the widespread adoption of TAT, it is essential to establish a decentralized production and distribution network for ²¹¹At across multiple facilities. In Japan, the high density of cyclotron-equipped institutions and the country’s compact geography offer a unique advantage: a well-coordinated supply network can be established to form a comprehensive treatment region despite the short half-life of 211At. However, it has currently revealed that ²¹¹At is supplied in varying chemical forms depending on the production facility, due to differences in bismuth target properties, irradiation parameters, and separation and purification methods. Among these, certain variations can alter the chemical species of astatine present in the final product, potentially affecting the efficiency of downstream radiolabeling. To ensure the reproducibility and reliability of radiopharmaceutical synthesis using ²¹¹At across different sites, standardization of its chemical quality is therefore indispensable. As an initial step toward this goal, we investigated the impact of irradiation conditions and separation/purification procedures on the chemical species of ²¹¹At in methanol solutions supplied by multiple production facilities. |
