基于医用质子直线注入器的超高剂量率细胞辐照实验平台的设计  

Design of an ultra-high dose rate cell irradiation experimental platform using a medical proton linear injector

作　　者：刘俊雅 喻晓 吴超 孙向上 商海焦 廖文涛 严南 周云 蒲越虎 LIU Junya;YU Xiao;WU Chao;SUN Xiangshang;SHANG Haijiao;LIAO Wentao;YAN Nan;ZHOU Yun;PU Yuehu(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China;SemicoreZKX Co.Ltd.,Beijing 101111,China;Medical Equipment Innovation Research Center,West China Hospital,Sichuan University,Chengdu 610041,China;Department of Radiation Physics and Technology,Hunan Cancer Hospital,Changsha 410013,China;RaySearch China,Shanghai 200120,China)

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]中国科学院大学,北京100049 [3]北京烁科中科信电子装备有限公司,北京101111 [4]四川大学华西医院医学装备创新研究中心,成都610041 [5]湖南省肿瘤医院放射物理技术部,长沙410013 [6]RaySearch中国,上海200120

出　　处：《核技术》2023年第11期1-11,共11页Nuclear Techniques

基　　金：国家重点研发计划项目(No.2016YFC0105408)资助。

摘　　要：为了系统研究FLASH效应的放射生物学机制,需要一个可以进行超高剂量率细胞辐照实验的平台,该实验平台应具有稳定、大小合适且大范围可调的剂量和平均剂量率。基于国产7 MeV医用质子直线注入器,使用蒙特卡罗程序FLUKA设计并优化了一个单散射照射头。该照射头的材料为40μm厚度的钽箔,它既充当真空窗又充当散射体,源皮距为26 cm。经过模拟验证,该平台可提供直径为2 cm的照射野,剂量均匀度为4.9%。通过调整单质子脉冲的流强(0.1~1 mA)和脉宽(20~200μs),该实验平台的平均剂量和平均剂量率可以在6~667Gy和3.3×10^(5)~3.3×10^(6)Gy·s^(-1)之间调节。基于此,设计了使用单脉冲穿透模式辐照单层细胞的实验,剂量率为3.3×10^(5)Gy·s^(-1),剂量在7~40Gy范围内变化。该实验平台可以探究细胞FLASH效应的总剂量依赖关系,为揭示FLASH效应的机制提供支持。[Background]Ultra-high dose rate(UHDR)radiation of electron or proton beam has been shown to spare normal tissues surrounding the tumors while killing tumor cells effectively which is called the FLASH effect(FE).However,the internal mechanisms of FE has not yet been fully revealed,and the optimal parameter range for its use remains unknown.[Purpose]This study aims to design an UHDR cell irradiation experimental platform that provides a stable,appropriate and wide range of adjustable dose and average dose rates for exploring the FE dependence on total dose.[Methods]Based on a 7 MeV medical proton linear injector,a single scattering nozzle was designed and optimized using the Monte Carlo code FLUKA.A 40-μm-thick tantalum foil,acting as both a vacuum window and a scatterer,was comprised in the nozzle with a source-to-surface distance of 26 cm.Finally,a single pulsed shoot-through UHDR cell penetration irradiation experiment was conducted by simulation using optimized parameters for this platform.[Results]The simulation results demonstrate that the experimental platform can provide a 2 cm diameter irradiation field with a dose homogeneity of 4.9%.By adjusting the beam intensities(0.1~1 mA)and pulse widths(20~200μs)of proton beam pulses,the dose and corresponding average dose rate of this platform can be adjusted within the range of 6~667 Gy and 3.3×10^(5)~3.3×10^(6)Gy·s^(-1),respectively.Results of simulated UHDR cell irradiation experiment show that the monolayer cells can be irradiated using a single pulsed shoot-through mode with a dose rate of 3.3×10^(5)Gy·s^(-1)and doses ranging from 7~40 Gy.[Conclusion]This platform enables UHDR experiments to explore the FE dependence on total dose,providing further experimental data for clarifying the FE mechanisms.

关 键 词：FLASH 质子治疗 蒙特卡罗 实验平台设计 医用直线注入器 

分 类 号：TL501.5[核科学技术—核技术及应用] TL503.4