摘要
目的:探究脊形滤波器结构对质子束流展宽的影响。方法:利用蒙特卡罗程序FLUKA建立质子束流模型,并进行验证。模拟质子束流通过三棱柱型(A型)和金字塔型(B型)两种脊形滤波器,比较使用和不使用脊形滤波器的模拟值:束流前端最大剂量50%到束流末端最大剂量50%的宽度(E50-D50)、束流前端80%到束流末端80%的宽度(E80-D80)及束流末端80%到束流末端20%的宽度(D80-D20)。结果:根据模型计算出的121.1 MeV质子对应的模拟值绘制的积分深度剂量曲线与实际测量的积分深度剂量曲线,E50、E70和D80位置偏差不超过0.06 mm;A型相比B型将E50-D50平均多展宽了0.80 mm,将E80-D80平均多展宽了0.27 mm,将D80-D20平均多展宽了0.08 mm。结论:建立的质子束流蒙特卡罗模型合理,三棱柱型(A型)脊形滤波器展宽质子束流的效果更好。
Objective To explore the effect of ripple filter structure on the broadening of proton beams.Methods Monte Carlo program FLUKA was used to establish a proton beam model,and the model was verified.The situations that proton beams passed through triangular prism type(A-type)and pyramid type(B-type)ripple filters were simulated,and the simulation data when the ripple filter was used or not were compared.The simulation data included the width between 50%of the maximum dose of the beam entrance and 50%of the maximum dose of the distal beam(E50-D50),the width between 80%of the maximum dose of the beam entrance and 80%of the maximum dose of the distal beam(E80-D80)and the width between 80%of the maximum dose of the distal beam and 20%of the maximum dose of the distal beam(D80-D20).Results The difference of E50,E70 and D80 between the integral depth dose curve plotted according to the simulation value of 121.1 Me V proton calculated by the model and the actually measured integral depth dose curve was no more than 0.06 mm.The E50-D50,E80-D80 and D80-D20 broadened by A-type ripple filter was 0.80,0.27 and 0.08 mm wider than those broadened by B-type ripple filter.Conclusion The Monte Carlo model of proton beams is proved to be reasonable,and the triangular prism type(A-type)ripple filter has better effect on broadening the proton beams.
作者
康月航
盛尹祥子
赵静芳
章青
KANG Yuehang;SHENG Yinxiangzi;ZHAO Jingfang;ZHANG Qing(Department of Medical Physics,Shanghai Proton and Heavy Ion Center,Shanghai 201321,China;Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy,Shanghai 201321,China;Department of Radiation Oncology,Hehai University Shanghai Cancer Center,Shanghai 200032,China;Department of Radiation Oncology,Shanghai Proton and Heavy Ion Center,Shanghai 201321,China)
出处
《中国医学物理学杂志》
CSCD
2020年第5期535-540,共6页
Chinese Journal of Medical Physics
基金
申康三年行动计划(16CR3097B)。
