Evaluation of DNA damage induced by low tube voltage CT scan used in the clinical setting: In-vitro study

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K10280
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Radiation science
• Research Institution: Hiroshima University
• Principal Investigator: AWAI Kazuo 広島大学, 医歯薬保健学研究科(医), 教授 (30294573)
• Co-Investigator(Kenkyū-buntansha): 福本 航 広島大学, 医歯薬保健学研究科(医), 特任助教 (00726870) ; 石田 万里 広島大学, 医歯薬保健学研究科(医), 准教授 (30359898) ; 中浦 猛 熊本大学, 大学院生命科学研究部(医), 特任講師 (90437913)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: CT / 低電圧撮像 / DNA / γ-H2AX

Outline of Final Research Achievements

The purpose of this study was to evaluate the DNA damage induced by low tube voltage CT scan used in the clinical setting.We obtained blood samples from five volunteers. Each blood samples were divided into ten samples and prepared with or without contrast media (CM). Eight samples with or without CM were inserted into a phantom and scanned with tube voltages of 80, 100, 120 and 135 kVp. Two samples with or without CM were not irradiated as control. To evaluate DNA damage, γ-H2AX foci formation in lymphocytes was quantified.
Regardless of the presence of CM, the numbers of γ-H2AX foci were increased after CT (without CM, p = 0.045; with CM, p = 0.015). There was no significant difference in the γ-H2AX focus formation among different tube voltage CT (without CM, p = 0.80; with CM, p = 0.40). Low tube voltage CT used in the clinical setting did not affect DNA damage in lymphocytes as long as radiation dose was managed in the same level.

Free Research Field

放射線診断学

Academic Significance and Societal Importance of the Research Achievements

CTにおいて低電圧撮像は被曝低減の重要な手法と位置づけられ、臨床応用が進められている。しかしながら、低電圧撮影は通常撮像と線質が異なり、これがDNA損傷にどのように影響を与えるかについて報告がない。本研究により、吸収線量が同一であれば、撮像電圧が異なってもDNAの二重鎖切断の程度はほとんど同一であり、生物学的影響はほとんど変化ないということが判明した。これにより低電圧撮像の生物学的安全性は、通常電圧撮像の際とほぼ同様と考えられた。