Assessment of Imprecise Small Photon Beam Modeling by Two Treatment Planning System Algorithms
Assessment of Imprecise Small Photon Beam Modeling by Two Treatment Planning System Algorithms
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通过两种治疗计划系统算法评估不精确的小光子束模型
DOI：
10.4103/jmss.jmss_28_17
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发表时间：
2018
影响因子：
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通讯作者：
A. Amouheidari
中科院分区：
文献类型：
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作者：
H. Keivan;D. Shahbazi;A. Shanei;A. Amouheidari
背景：调强放疗（IMRT）的剂量准确性是质量保证计划的重要组成部分。处理计划系统（TPS）对小场的光束建模不当会导致处理的不准确。本研究旨在评估二维（2D）阵列IMRT技术在小区域的剂量传递准确性，并评估两种tps算法在小区域建模中的能力。方法：采用西门子Artiste直线加速器的6 MV光子束照射。采用二维二极管阵列和伽玛评价，分析了两种剂量计算算法，即塌陷锥卷积/叠加（CCCS）和全散射卷积（FSC）在IMRT计划小片段中的剂量学行为。结果：测量结果与tps计算结果的比较表明，CCCS和FSC算法的小块田产出因子的百分比差异分别为2%和15%。对TPS计算的剂量分布与二维阵列测量的剂量分布进行Gamma分析表明，在3 mm/3%的通过率标准下，除TiGRT TPS优化的小于3 cm × 3 cm的片段外，所有片段尺寸的平均通过率均高于95%。结论：相对于TiGRT获得的结果，在计划的小段中，高超的伽玛指数达到了较高的通过率（95%）。研究表明，两种剂量计算算法的小场模拟精度存在差异。
Background: Dosimetric accuracy in intensity-modulated radiation therapy (IMRT) is the main part of quality assurance program. Improper beam modeling of small fields by treatment planning system (TPS) can lead to inaccuracy in treatment delivery. This study aimed to evaluate of the dose delivery accuracy at small segments of IMRT technique using two-dimensional (2D) array as well as evaluate the capability of two TPSs algorithm in modeling of small fields. Methods: Irradiation were performed using 6 MV photon beam of Siemens Artiste linear accelerator. Dosimetric behaviors of two dose calculation algorithms, namely, collapsed cone convolution/superposition (CCCS) and full scatter convolution (FSC) in small segments of IMRT plans were analyzed using a 2D diode array and gamma evaluation. Results: Comparisons of measurements against TPSs calculations showed that percentage difference of output factors of small fields were 2% and 15% for CCCS and FSC algorithm, respectively. Gamma analysis of calculated dose distributions by TPSs against those measured by 2D array showed that in passing criteria of 3 mm/3%, the mean pass rate for all segment sizes is higher than 95% except for segment sizes below 3 cm × 3 cm optimized by TiGRT TPS. Conclusions: High pass rate of gamma index (95%) achieved in planned small segments by Prowess relative to results obtained with TiGRT. This study showed that the accuracy of small field modeling differs between two dose calculation algorithms.
T.Inuzuka：“金刚石薄膜在异质基底上的外延生长”金刚石和相关材料。
DOI：
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发表时间：
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期刊：
影响因子：
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作者：
通讯作者：
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影响因子：
3.8
作者：
Carrasco, P;Jornet, N;Ribas, M
通讯作者：
Ribas, M