基于线性博尔兹曼运输方程的外部光束放射治疗剂量计算中的物质错误分配的剂量影响
Perumal Murugan1, Ravikumar Manickam2,3, Tamilarasan Rajamanickam1
1Sri Shankara Cancer Hospital and Research Centre, Bengaluru, Karnataka, India.
Radiological physics and technology
|August 23, 2025
概括
在Acuros XB (AXB) 中精确的物质分配对于放射治疗剂量计算至关重要. 错误的材料或质量密度会对剂量传递产生重大影响,特别是在空气-肺和软骨-骨的接口上,需要手动验证.
科学领域:
- 医学物理
- 放射治疗物理
- 计算剂量计
背景情况:
- 精确的剂量计算在现代放射治疗中至关重要.
- Acuros XB (AXB) 是Eclipse治疗计划系统 (TPS) 中使用的高级剂量计算算法.
- 来自CT扫描的材料和质量密度分配是AXB的关键输入.
研究的目的:
- 在Acuros XB (AXB) 剂量计算中评估材料和质量密度错误的影响.
- 评估这些错误分配在临床场景中的频率和后果.
- 确定材料分配是否需要手动验证.
主要方法:
- 使用受控材料和质量密度错误的幻影模拟.
- 用三台扫描仪对270名患者CT扫描进行临床分析,以评估Hounsfield单位 (HU) 的变化.
- 在96名放射治疗患者的剂量偏差分析中,使用D98%,Dmean和D2%的指标比较自动和手动的物质分配.
主要成果:
- 材料的错误分配导致了大量的剂量差异 (例如,空气-肺部的12. 1%,软骨-骨的2. 8%).
- 错误的质量密度导致剂量变化高达5. 5% (肺空气) 和2% (骨).
- 临床分析显示,鼻腔空气经常被错误地归类为肺部,导致显著的剂量偏差 (D98%为11. 8%).
结论:
- 在AXB剂量计算中出现的物质错误导致了显著的剂量测量错误.
- 精确的物质分配对于放射治疗中精确的剂量分配至关重要.
- 自动分配材料的手动验证是必要的,特别是在容易错误分类的复杂解剖区域.
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