评估对矩形小字段的等价方形字段大小定义
Ignasi Méndez1, Mateb Al Khalifa2,3, Haya Aljuaid2
1Department of Dosimetry and Quality of Radiological Procedures, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
Journal of applied clinical medical physics
|February 10, 2026
概括
这项研究评估了用于放射治疗的矩形小场转换为等效方形场的方法,发现Fogliata模型是计算场输出因子 (FOF) 最准确的. 这改进了国际原子能机构对矩形字段的TRS-483行为准则 (CoP).
科学领域:
- 医学物理 医学物理
- 辐射瘤学 辐射瘤学
- 剂量测量方法 剂量测量方法
背景情况:
- 国际原子能机构的TRS-483行为准则 (CoP) 使用克兰默-萨尔吉森定义,以将矩形小字段与相当的方形字段相近.
- CoP对这种近似的不确定性估计仅限于面积比在0.7到1.4之间的矩形字段.
研究的目的:
- 为了比较Cranmer-Sargison定义的准确性与等等方形场的替代公式.
- 评估这些公式用于测量矩形小场的场输出因子 (FOF),无论是在COP的指定范围内还是外.
主要方法:
- 放射色膜 (Gafchromic EBT4) 用于进行测量.
- 进行比较的定义包括克兰默-萨尔吉森,斯特林,超,斯特林部分超,斯特林超,瓦达什和比恩加德以及福利塔.
- 精度是通过测量和分析FOF值之间的最小差异来确定的,用日志概率作为度量.
主要成果:
- 福利亚特模型表现出最高的准确性,其次是斯特林部分超圆.
- 斯特林-超和瓦达什和Bjärngard模型也表现良好.
- 斯特林部分超和斯特林超模型仅依赖于场地几何,而Fogliata和Vadash和Bjärngard包括一个合适的参数.
- 英的定义在克兰默-萨吉森的定义上得到了改进,但不那么准确.
- 克兰默-萨吉森和超模型显示出最大的差异.
结论:
- 几个相当的方形小场面大小定义可以增强国际原子能机构TRS-483 CoP的矩形场面.
- 福利雅塔模型为矩形小场的场输出校正因子提供了最准确的结果.
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