Selective Internal Radiotherapy by Secondary Electrons Emitted from Non-Radioactive Drugs Taken by Cancer Cells

2018 Fiscal Year Final Research Report

• Project/Area Number: 25282152
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Medical systems
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Oguri Yoshiyuki 東京工業大学, 科学技術創成研究院, 教授 (90160829)
• Co-Investigator(Kenkyū-buntansha): 長谷川 純 東京工業大学, 科学技術創成研究院, 准教授 (90302984) ; 近藤 康太郎 東京工業大学, 原子炉工学研究所, 助教 (80582593)
• Research Collaborator: Fukuda Hitoshi
• Project Period (FY): 2013-04-01 – 2019-03-31
• Keywords: 低侵襲ガン治療 / 吸収線量 / 放射線増感剤 / オージェ電子 / X線吸収端 / 単色X線 / 荷電粒子励起X線放出 / 静電加速器

Outline of Final Research Achievements

In cancer radiotherapy, generally, patients usually suffer from radiation hazard as a side effect, since not only cancer cells but also normal cells are irradiated. However, if a cancer cell is loaded with a nonradioactive drug containing heavy atoms, and then irradiated with monochromatic X-rays of an appropriate energy, many secondary electrons are emitted from the heavy atoms. Thus, only the cancer cell can be internally irradiated. To examine the feasibility of this method, we irradiated a thin metal foil simulating these heavy atoms with proton-induced monochromatic X-rays, and measured the dose distribution around the foil. As a result, we found that the dose was greatly increased around the foil. Therefore, a similar dose increase due to secondary electrons can be expected around heavy atoms ingested by cancer cells, indicating the possibility of applying this method to minimally invasive cancer treatment.

Free Research Field

イオンビーム応用工学

Academic Significance and Societal Importance of the Research Achievements

工学的には原子核反応に比べてはるかに容易に実現できる原子過程を利用してホウ素中性子捕捉療法（BNCT）と同様な効果を実現する点に意義がある．また通常の医療用連続X線に代え，陽子線励起単色X線によりガン細胞が取り込んだ目的の原子のみを電離し，正常組織への影響を抑える点がポイントである．原理的に重粒子線治療やBNCT等と比較して低コストであり，開発が進めば広く普及する可能性がある．高浸潤性ガンの治療という極めて要請の強い技術分野であり，社会的意義は大きい．また加速器技術に関係しており，医療機器産業のみならず電気電子，重電，原子力等の分野の需要を刺激し，新たな産業分野を生む可能性も期待できる．