Evaluation of normal organs tolerance dose including individual radiosensitivity for chemoradiotherapy in esophageal cancer patients

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K16447
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Radiation science
• Research Institution: Hiroshima University
• Principal Investigator: Nishibuchi Ikuno 広島大学, 病院(医), 講師 (70595834)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 食道癌 / 化学放射線療法 / 放射線感受性 / DNA損傷

Outline of Final Research Achievements

Traditionally, the prediction of adverse events due to radiotherapy has been based on radiation dose and extent, and individual radiosensitivity has not been taken into account. In this study, we measured DNA damage and chromosome aberrations in lymphocytes of esophageal cancer patients undergoing chemoradiotherapy and examined the relationship between the temporal changes in DNA damage and chromosome aberrations and individual radiosensitivity and adverse events.
The results showed that the number of chromosome aberrations varied among individuals and that the number of aberrations was significantly increased in patients who developed severe acute non-hematologic toxicity. The number of chromosome aberrations may be a predictive marker for the occurrence of adverse events, suggesting that it is useful for the completion of tolerable dose assessment of normal tissues based on their sensitivity.

Free Research Field

放射線治療

Academic Significance and Societal Importance of the Research Achievements

近年の高精度放射線治療技術の進歩により、腫瘍組織への線量を担保しながら、周囲正常組織への線量を低減することが可能となっている。しかしながら、正常組織の耐容線量は個々の患者の放射線感受性によらず一定とみなして、放射線治療計画を行っているのが現状である。
本研究により、照射により生じる染色体異常数と有害事象には相関がある可能性が示唆された。個々の患者の染色体異常数を評価することにより、それぞれの放射線感受性に応じた線量制約を設けることが可能となれば、より安全に化学放射線療法が施行できるようになるものと考える。