Establishment of a method for predicting bone marrow suppression after I-131 MIBG treatment using flow cytometry

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K08128
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Kanazawa University
• Principal Investigator: WAKABAYASHI HIROSHI 金沢大学, 附属病院, 講師 (60622818)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 放射線 / 核医学 / 被ばく / DNA / フローサイトメトリー / リンパ球

Outline of Final Research Achievements

This study aims to establish a simple method for predicting myelosuppression using γ-H2AX, a DNA damage indicator, to measure the degree of lymphocyte damage after radiotherapy by flow cytometry. Lymphocyte damage after external and internal irradiation was evaluated by flow cytometry using γ-H2AX to examine exposure dose, the degree of lymphocyte damage, and changes in lymphocyte damage over time. DNA damage of lymphocytes due to external irradiation was positively correlated with absorbed dose. Recovery from damage caused by external irradiation was observed within 3 days, while lymphocyte damage caused by low-dose internal irradiation was observed to recover within 24 hours. Flow cytometry was an effective method to assess radiation-induced DNA damage quantitatively.

Free Research Field

核医学

Academic Significance and Societal Importance of the Research Achievements

本研究では、DNA損傷指標のγ-H2AXを用いて、放射線治療後のリンパ球障害の程度をフローサイトメトリーで測定する簡易な骨髄抑制予測法の確立を目指した。フローサイトメトリーで評価できる放射線外照射後のリンパ球障害の程度は線量と相関関係があり、障害の回復過程も確認できた。I-131によるリンパ球障害はフローサイトメトリーでの検出が可能であった。日本の放射線同位元素（RI）治療で用いられる核種は主にI-131であり、本研究の結果は我が国におけるRI治療後の被ばく管理に応用できる。フローサイトメトリーによる評価はRI治療後の被ばく管理に応用でき、広く役立つと考えられる。