Initial Experiences on the Production of Astatine-211 at Fukushima Medical University using “CYPRIS MP-30” Cyclotron
Takashi Oda (1), Kohshin Washiyama (2), Miho Aoki (2), Manami Taniguchi (1), Jun Kato (1), Francisco Guerra Gomez (1), Toru Ishizuka (1), Kazuhiro Takahashi (2)
(1) Sumitomo Heavy Industries, Ltd., (2) Fukushima Medical University
Poster
The authors declare no conflicts of interest associated with this manuscript.
Research concerning the production of alpha emitting radionuclides for targeted alpha-particle therapy has increased in recent years. Particularly, At-211 is of great interest since it is producible at medium energy cyclotrons and desirable nuclear properties. At-211 is formed on bismuth via 209Bi(a, 2n)211At nuclear reaction (Ethr = 20.7 MeV). However, the concomitant 209Bi(a, 3n)210At process (Ethr = 28.6 MeV) must be avoided due to the toxicity of its decay product Po-210, leaving the window for At-211 production from 20 to 28.6 MeV. On the other hand, targetry poses technical challenges due to the bismuth poor thermal conductivity, low melting point and vaporization of At-211. CYPRIS MP-30 cyclotron and its vertical irradiation system developed by Sumitomo and installed at Fukushima Medical University, accelerates alpha particles up to 32 MeV, suitable for At-211 production. The bismuth is placed inside a metallic capsule closed on top by an aluminum foil that serves also as energy degrader. After irradiation the capsule is automatically removed, and At-211 is separated from bismuth matrix by dry distillation. In this work, the initial experiences of a joint development project dedicated to the optimization At-211 production are presented.