| Sun Jianhan,Kong Xianghui,Lyu Jianfeng,et al.Study on the radical kinetics driven by the beam time profile under different oxygen contents in FLASH radiotherapy[J].Chinese Journal of Radiological Medicine and Protection,2025,45(11):1061-1068 |
| Study on the radical kinetics driven by the beam time profile under different oxygen contents in FLASH radiotherapy |
| Received:June 24, 2025 |
| DOI：10.3760/cma.j.cn112271-20250624-00213 |
| KeyWords:FLASH radiotherapy Free radicals Monte Carlo simulation Beam physics |
| FundProject:国家自然科学基金(12275012,12475309,12411530076,12375334,12581360004,82202941);北京市自然科学基金(Z210008);国家重点研发计划项目(2019YFF01014402);北京大学肿瘤医院临床研究青年基金(QNJJ2023018);中央高校基本科研业务费/北京大学临床医学+X青年专项(PKU2025PKULCXQ014);教育部内地与港澳高等学校师生交流计划项目(万人计划7111400072);内蒙古自治区科技计划项目(2022YFSH0064) |
| Author Name | Affiliation | E-mail | | Sun Jianhan | State Key Laboratory of Nuclear Physics and Technology, Peking University School of Physics, Beijing 100871, China
Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China | | | Kong Xianghui | Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China | | | Lyu Jianfeng | State Key Laboratory of Nuclear Physics and Technology, Peking University School of Physics, Beijing 100871, China
Beijing Laser Acceleration Innovation Center, Beijing 101407, China | | | Wang Jinghui | Beijing Laser Acceleration Innovation Center, Beijing 101407, China
Guangdong Institute of Laser Plasma Accelerator Technology, Guangzhou 510540, China | | | Liu Xiaodong | State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, China | | | Lin Chen | State Key Laboratory of Nuclear Physics and Technology, Peking University School of Physics, Beijing 100871, China
Beijing Laser Acceleration Innovation Center, Beijing 101407, China | | | Li Tian | Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China | | | Zhang Yibao | Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China | | | Huang Senlin | State Key Laboratory of Nuclear Physics and Technology, Peking University School of Physics, Beijing 100871, China | huangsl@pku.edu.cn |
|
| Hits: 3322 |
| Download times: 512 |
| Abstract:: |
| Objective To reveal the coupling mechanism of beam temporal profile and tissue oxygen content on radical kinetics, further explain the potential biological basis of the FLASH effect, and provide a reference for beam optimization and treatment planning design of FLASH radiotherapy (FLASH-RT). Methods TOPAS-nBio v3.0 was used to simulate the physical and chemical processes of electron beams in water, and a full-scale kinetic model was established covering the generation, diffusion, reaction, and quenching of free radicals such as hydroxyl radical (·OH) and hydrated electrons (eaq-). Under different beam temporal profiles (single pulse, multi-pulses, continuous wave irradiation) and different oxygen concentration conditions, the evolution dynamics of free radicals were systematically simulated. At the same time, the data on eaq- content were obtained by experimental measurement of laser absorption spectroscopy to verify the accuracy of the model prediction. Results The changing trend of eaq- concentration measured in the experiment was highly consistent with the simulation result, verifying the reliability of the constructed model. The beam time structure had a significant impact on the peak value and duration of free radical concentration. The single-pulse structure can cause the free radicals to rapidly increase and then quickly quench in a short time, while the continuous or long-pulse structure can cause the radical concentration to remain at a high level for a long time. The evolution of ·OH was not sensitive to the oxygen environment, while eaq- are greatly affected by the oxygen environment. The scavenging efficiency of free radicals in a hypoxic environment was significantly decreased, leading to an enhanced accumulation of oxidative damage to biological macromolecules. The lifespan of eaq- in an oxygen-rich environment decreased rapidly. Conclusions Radical kinetics are regulated by both the beam temporal profile and oxygen content. FLASH-RT can utilize single-pulse or multi-pulses intervals to form periodic windows, reducing normal tissue damage by efficiently scavenging free radicals through antioxidants, while free radicals in tumor tissues continuously accumulate and amplify damage, thus generating a selective protective effect. |
| HTML View Full Text View/Add Comment Download reader |
| Close |
|
|
|
