在18 MV的小现场输出校正因子
Jonas Ringholz1, Otto A Sauer1, Sonja Wegener1
1Department of Radiation Oncology, University Hospital Würzburg, Würzburg, Germany.
Medical physics
|August 2, 2023
概括
这项研究确定了各种探测器的场输出校正因子,在18 MV的放射治疗能量下. 大多数探测器需要比较低的能量更大的校正,从而提高了光束数据的准确性.
科学领域:
- 医学物理 医学物理
- 放射治疗 物理 物理
- 辐射检测 辐射检测 辐射检测
背景情况:
- 有限的数据存在于探测器响应在18 MV放射治疗能量,影响治疗规划的准确性.
- 目前的指导方针 (TRS-483) 主要涵盖小田6MW和10MW的能量.
- 准确的现场输出因子对于放射治疗中精确的剂量分配计算至关重要.
研究的目的:
- 通过确定各种探测器的现场输出校正因子来解决18 MV的数据缺口.
- 为了研究探测器响应在18 MV的能量依赖性.
- 为准确的放射治疗治疗计划提供必要的数据,以更高的能量.
主要方法:
- 评估了多个探测器 (离子室,二极管,闪器,薄膜) 使用一个ELEKTA Versa HD加速器在18 MV.
- 在10厘米深处测量剂量反应,方形场的边长从0.5到10厘米不等.
- 使用放射色膜和兼容的室内数据作为分别用于小和大场的参考,遵守TRS-483协议.
主要成果:
- 闪器 (W2 1x1) 和剃刀室与参考数据的偏差最小.
- 屏蔽二极管在小领域表现出最高的过度响应,其次是其他二极管和microDiamond.
- 电离室表现出体积效应,在小领域显著低于响应 (Semiflex高达30%).
- 18 MV的校正通常比6和10 MV更大,除了PinPoint 3D室.
结论:
- 对于18MV的能量,在不同尺寸的场中成功确定了场输出校正因子.
- 大多数探测器在18 MV需要更大的校正,而不是6和10 MV.
- 实施这些校正因子将提高18 MV放射治疗应用的光束数据的准确性.
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