Comparison of small photon beams measured using radiochromic and silver-halide films in solid water phantoms.
Comparison of small photon beams measured using radiochromic and silver-halide films in solid water phantoms.
复制标题
在固体水体模中使用放射变色膜和卤化银膜测量的小光子束的比较。
DOI：
10.1118/1.1788931
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发表时间：
2004
期刊：
影响因子：
3.8
通讯作者：
Dempsey,JamesF
中科院分区：
文献类型：
--
作者：
Zeidan,OmarA;Li,JonathanG;Low,DanielA;Dempsey,JamesF
在这项研究中，我们比较了四种最常用的兆伏光子束剂量学薄膜在相同条件下用小多叶准直器(MLC)定义的光束照射时的剂量学特性。两种卤化银膜(SHF)，柯达XV2和EDR2，以及两种辐射变色膜(RCF)，Gafchroic HS和MD55-2，由配备120叶MLC的瓦里安直线加速器定义的束流照射。将加速器台架横向(旋转)放置在源-表面距离的固体水压缩膜模体上，使膜平行于束轴放置，从而交付束流。对于叶端和叶侧定义的梁，在中心轴和离轴上传递束。胶片剂量测定是使用定量光密度(OD)成像系统进行的，该成像系统在先前的研究中得到了验证。SHF和RCF测量之间在中心轴和离轴测量的深度剂量百分比、水平深度分布或二维空间等剂量分布方面没有显著差异。我们发现，无论所使用的胶片类型是RCF还是SHF，都可以生成用于小束剂量建模的一致的数据集。以前基于RCF和OD成像系统的验证研究表明，对于小束表征，所有胶片都能产生准确的结果。
In this study, we compared the dosimetric properties of four of the most commonly used films for megavoltage photon‐beam dosimetry when irradiated under identical conditions by small multileaf‐collimator (MLC) defined beamlets. Two silver‐halide films (SHFs), Kodak XV2 and EDR2, and two radiochromic films (RCFs), Gafchromic HS and MD55‐2, were irradiated by MLC‐defined beamlets from a Varian linac equipped with a 120‐leaf MLC. The beamlets were delivered with the accelerator gantry set laterally ( rotation) upon a solid‐water compression film phantom at source‐to‐surface distance which was positioned with the films parallel to the beam axis. Beamlets were delivered at central axis, , and off‐axis for both leaf‐end and leaf‐side defined beamlets. The film dosimetry was performed using a quantitative optical density (OD) imaging system that was validated in a previous study. No significant differences between SHF and RCF measurements were observed in percentage depth doses, horizontal depth profiles, or two‐dimension spatial isodose distributions in both the central axis and off‐axis measurements. We found that regardless of the type of film used, RCF or SHF, a consistent data set for small beam dose modeling was generated. Previous validation studies based on the use of RCF and OD imaging system would indicate that all film produce an accurate result for small beam characterization.