[1]韩俊杰,陈立新,朱金汉,等.Varian Edge均整和非均整模式下6 MV和10 MV光子线能谱研究[J].中国医学物理学杂志,2018,35(9):997-1004.[doi:DOI:10.3969/j.issn.1005-202X.2018.09.002]
　HAN Junjie,CHEN Lixin,ZHU Jinhan,et al.Energy spectra of 6 and 10 MV flattened and flattening filter-free photon beams from Varian Edge[J].Chinese Journal of Medical Physics,2018,35(9):997-1004.[doi:DOI:10.3969/j.issn.1005-202X.2018.09.002]
点击复制

Varian Edge均整和非均整模式下6 MV和10 MV光子线能谱研究()
分享到：

《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]

卷:
35卷
期数:
2018年第9期
页码:
997-1004
栏目:
医学放射物理
出版日期:
2018-09-27

文章信息/Info

Title:
Energy spectra of 6 and 10 MV flattened and flattening filter-free photon beams from Varian Edge
文章编号:
1005-202X（2018）09-0997-08
作者:
韩俊杰1; 陈立新2; 朱金汉2; 潘燚1; 梁瑜1; 王学涛3; 张白霖3; 邹文长1
1. 广东省人民医院放疗科, 广东广州510080；2. 中山大学附属肿瘤医院放疗科/华南肿瘤学国家重点实验室，广东广州510060； 3.广东省中医院放疗科，广东广州510120
Author(s):
HAN Junjie1;  CHEN Lixin2;  ZHU Jinhan2;  PAN Yi1;  LIANG Yu1; WANG Xuetao3;  ZHANG Bailin3;  ZOUWenchang1
1. Department of Radiation Oncology, Guangdong General Hospital, Guangzhou 510080, China; 2. State Key Laboratory of Oncology in South China/Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China; 3. Department of Radiation Oncology, Guangdong Traditional Chinese Medicine Hospital, Guangzhou 510120, China
关键词:
光子线; 能谱; 均整模式; 非均整模式; Varian Edge; EGSnrc
Keywords:
Keywords: photon beam;  energy spectrum;  flattening filter model;  flattening filter-free model;  Varian Edge;  EGSnrc
分类号:
R811.1
DOI:
DOI:10.3969/j.issn.1005-202X.2018.09.002
文献标志码:
A
摘要:
目的：研究Varian Edge均整（FF）和非均整（FFF）模式下6 MV和10 MV 光子线能谱并对比其差异。方法：利用 蒙特卡洛程序软件包EGSnrc/Beamnrc建立Varian Edge 6 MV FF和FFF、10 MV FF和FFF的加速器模型，模拟所对应的 相空间文件，而后以相空间作为输入源，利用DOSXYZnrc计算其在水体模中的剂量分布，并与三维水箱的测量数据比 对，当模拟值与测量值之间的差异在1%之内时，利用Beamdp分析此时的相空间文件，得到对应的光子线能谱，并比较相 互之间的差异。结果：模拟的百分深度剂量曲线和离轴比曲线与测量值之间的差异在1%之内。相对于FF模式，FFF模式 的能谱“软化”，其中6 MV FFF 的平均能量从1.587 MeV 下降至1.172 MeV，低能（能量≤1 MeV）光子所占的份额由 41.06%上升至60.04%；而10 MV FFF的平均能量从2.796 MeV下降至1.956 MeV，低能光子所占的份额由21.22%上升至 44.63%。同一射野内FFF模式的能谱随离轴距离的改变较小，同时每初始粒子所引起的能量注量是FF模式的2~4倍，射 野内的能量注量分布变得不均匀，非平坦度F上升；分析不同射野下的能谱发现FFF模式的机头散射较少。结论：本研究 结果对理解FFF模式下光子线的物理特性提供了非常好的参考价值。
Abstract:
Abstract: Objective To study the energy spectra of 6 and 10MV flattening filter (FF) and flattening-filter-free (FFF) photon beams from Varian Edge and compare their differences. Methods Monte Carlo program package, EGSnrc/Beamnrc, was used to establish Varian Edge models, including 6 MV FF and FFF, 10 MV FF and FFF, and the corresponding phase space files were simulated. Then with the phase space as input source, DOSXYZnrc was applied to measure the dose distributions in water phantom which were compared the simulated results obtained with three-dimensional water tank. If the differences between measurement and simulation were within 1%, the phase space files were analyzed with Beamdp in order to obtain the energy spectra. The differences among those obtained energy spectra were also compared. Results The differences of percentage depth dose and off axis ratio between simulation and measurement were within 1%. Compared with that of FF model, the energy spectra of FFF model became softer. The mean energy of 6 MV FFF decreased from 1.587 MeV to 1.172 MeV, and the percentage of low-energy photon (≤1 MeV) increased from 41.06% to 60.04%. The mean energy of 10 MV FFF decreases from 2.796 MeV to 1.956 MeV, and the percentage of low-energy photon increased from 21.22% to 44.63%. In the same field, the energy spectra of FFF model had slight changes with the increase of off axis distance, but the energy fluence caused by per initial particle was 2 to 4 times of FF model. Meanwhile, compared with that of FF model, the energy fluence distribution of FFF model became uneven, with a raising unflatness F. The analysis on the energy spectra in different fields revealed that the scattering from FFF accelerator head was less. Conclusion This study provides valuable references for the comprehension about the physical characteristic of FFF photon beams.

相似文献/References:

[1]戴春艳,刘永明,于春山,等.G4射波刀治疗头的蒙特卡罗模拟[J].中国医学物理学杂志,2016,33(5):525.[doi:10.3969/j.issn.1005-202X.2016.05.019]
　[J].Chinese Journal of Medical Physics,2016,33(9):525.[doi:10.3969/j.issn.1005-202X.2016.05.019]
[2]岳海振,张艺宝,张健,等. 基于蒙特卡罗方法的光子束均整与非均整模式能谱对比分析[J].中国医学物理学杂志,2018,35(6):633.[doi:DOI:10.3969/j.issn.1005-202X.2018.06.003]
　YUE Haizhen,ZHANG Yibao,ZHANG Jian,et al. Comparison analysis of energy spectra between flattened and flattening-filter-free Monte Carlo models for photon beam[J].Chinese Journal of Medical Physics,2018,35(9):633.[doi:DOI:10.3969/j.issn.1005-202X.2018.06.003]

备注/Memo

备注/Memo:
【收稿日期】2018-05-09 【基金项目】广东省自然科学基金（2016A030313276，2014A030310188）；广州市科技计划项目（20160701168） 【作者简介】韩俊杰，研究方向：蒙特卡洛算法在放疗中的应用，E-mail: 1259432066@qq.com 【通信作者】陈立新，博士，副研究员，E-mail: chenlx@sysucc.org.cn；潘燚，博士，主任医师，E-mail: panyiff01@163.com
更新日期/Last Update: 2018-09-28