Evaluation of radiotoxicity after Ra-223 therapy using gamma-H2AX foci formation in lymphocytes.

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K10366
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Radiation science
• Research Institution: Kanazawa Medical University
• Principal Investigator: WATANABE Naoto 金沢医科大学, 医学部, 教授 (40210926)
• Co-Investigator(Kenkyū-buntansha): 岩淵 邦芳 金沢医科大学, 医学部, 教授 (10232696) ; 道合 万里子 金沢医科大学, 医学部, 講師 (40515673)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 塩化ラジウムー２２３ / DNA損傷 / リンパ球 / 放射線障害

Outline of Final Research Achievements

Our study was to evaluate the degree of radiotoxicity to lymphocytes after radium-223 therapy using γ-H2AX foci immunodetection. We studied 4 patients who were treated with Ra-223 totally 12 times. Lymphocytes were isolated from the blood samples and subjected to γ-H2AX immunofluorescence staining. A total of 50 lymphocytes were visually evaluated. The number of foci per lymphocyte nucleus was 0.47 ± 1.09 before and 0.72 ± 1.34 after therapy, and this difference was statistically significant (P<0.001). γ-H2AX foci immunodetection in lymphocytes may detect radiation-induced DNA damage associated with Ra-223 therapy.

Free Research Field

核医学

Academic Significance and Societal Importance of the Research Achievements

実際には塩化ラジウム－２２３を用いた放射線内部照射治療では、様々な副作用が生じているが、重大な副作用としてリンパ球減少等の骨髄抑制があることは確認されている。その副作用を早期で評価できれば、副作用緩和にとって有用と考えられる。治療２４時間後のリンパ球をγ-H2AXを用いて免疫染色を行なって、リンパ球のＤＮＡ損傷を評価できるので、早期にある程度の骨髄のＤＮＡ損傷の一端を評価できると推測される。リンパ球のＤＮＡ損傷の障害程度によって、臨床上早期に副作用に対応できる有用性が示唆される。