Attempt of actinium -225 source production and the application for alpha-ray medical treatment

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K22596
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 52:General internal medicine and related fields
• Research Institution: Kyoto University
• Principal Investigator: Ohtsuki Tsutomu 京都大学, 複合原子力科学研究所, 特任教授 (50233193)
• Project Period (FY): 2019-06-28 – 2024-03-31
• Keywords: 医用放射性同位元素 / 線源内療法 / 加速器 / 研究用原子炉 / 分析技術 / 半減期 / 核分裂

Outline of Final Research Achievements

An Ac-225 has nuclear properties well suited for use in targeted alpha therapy and clinical trials have demonstrated the applicability of radiopharmaceuticals containing Ac-225 to treat various cancers. In this work, thus accelerator-based Ac-225 production systems have been developed. We have carried out an experimental study on the production of Ra-226(gamma,n)Ra-225 using an electron linear accelerator and here Ra-225 decays to Ac-225 for the objective targeted alpha therapy(TAT).
We pushed forward preparations to get associated knowledge including　the TAT for the application such as nano-containers of such alpha emitted nuclide (Ac-225)in C60, C70 and C82 fullerene in body. Furthermore, in nuclear data as the relation in the present work, we acquired the characteristics of half-life of small atomic number radioisotopes such as Be-7. Nuclear fission properties accompanied with the huge resonance in such as Th-232 and/or U-238 etc.

Free Research Field

放射化学

Academic Significance and Societal Importance of the Research Achievements

前立腺等のがんは年々増加しているのが現状であり、それに伴い、アルファ線放出核種(RI)による核医学治療が重要度を増してきている。しかし、日本では前立腺がんや骨がんの放射性薬剤としての認可を受けたばかりであり、この分野の早急な進展が望まれている。本研究では、ウラン系列の放射性廃棄物として多量に存在するラジウム-226（Ra-226）を、高エネルギーガンマ線を用いて前立腺がん等の核医学治療に有効なAc-225の製造を試み、RIナノコンテナなどへの応用を探るという学術的意義が大きい。また、関係する研究としてBe-7の半減期やU-238などの核データの新たな知見を得た。