Internal dose assessment considering biokinetic behavior after radiopharmaceutical administration

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K15795
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: Tani Kotaro 国立研究開発法人量子科学技術研究開発機構, 放射線医学研究所 計測・線量評価部, 主任研究員 (40736071)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 内部被ばく / 核医学 / 体内動態モデル

Outline of Final Research Achievements

This study evaluated the internal dose by considering individual differences in metabolism and morphology of 44 liver cancer patients who underwent liver scintigraphy with synthetic glycoprotein labeled with the radionuclide Tc-99m (Tc-99m-GSA). For the liver, which receives the highest radiation dose from Tc-99m-GSA, it was found that the variations in male patients were primarily due to the number of disintegrations influenced by metabolism. In contrast, for the female patients, variations were more attributable to the S value, which depends on morphology. Consequently, neither factor alone significantly contributes to the variation in radiation dose. This suggests that both metabolism and morphology should be considered when evaluating internal doses for specific persons.

Free Research Field

保健物理学

Academic Significance and Societal Importance of the Research Achievements

近年、予めγ線放出核種で標識した抗体の集積部位を核医学検査で確認した上で、α線／β線放出核種で標識した抗体によってがん細胞を死滅させる標的アイソトープ治療を実施するプロトコルの確立が検討されている。本研究の成果を、核医学検査に基づく各患者の代謝及び形態学的差異の把握と、標的アイソトープ治療によるがん組織及び正常臓器・組織の線量予測に役立てることにより、患者ごとに放射性薬剤の至適投与量を決定する個別化医療の実現に貢献できると期待される。