Dynamics of internal radionuclides distribution in the lymph nodes by quantum beam based elemental analysis

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K21163
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0908:Society medicine, nursing, and related fields
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: AYAMA Kyoko 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 放射線規制科学研究部, 技術員 (30953608)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: リンパ節 / ウラン / 内部被ばく / マイクロビーム / 元素イメージング

Outline of Final Research Achievements

To reduce the risk of internal exposure, radionuclides taken into the body must be efficiently decorporated from deposited and remaining sites. Lymph nodes are regarded as important organs in dose assessment for internal exposure, but quantitative data based on animal experiments are scarce. The purpose of this study was to elucidate the distribution kinetics of radionuclides in the lymph nodes of animals exposed to long-lived internal radionuclides by quantum beam based elemental analyses.
Uranium was administered subcutaneously or orally to rats, and uranium concentrations in the submandibular and mesenteric lymph nodes were determined by ICP-MS. Uranium concentrations in both lymph nodes were higher than plasma uranium concentrations. Frozen sections of lymph nodes were used for microbeam elemental imaging. Elemental mapping corresponding to the microstructural microstructure was obtained by micro-PIXE analysis. Uranium in lymph nodes was detected by SR-XRF.

Free Research Field

生体微量分析

Academic Significance and Societal Importance of the Research Achievements

本課題においてリンパ節という微細組織の微量ウラン検出条件を確立し、その移行動態を明らかにすることができた。血清ウラン濃度と比較して濃集が確認されたことから、中長期ウランばく露モデルに発展させることで、リンパ節ウランの沈着・滞留についての知見が得られ、線量評価の精緻化につながる。