Real-time prompt gamma monitoring in spot-scanning proton therapy using imaging through a knife-edge-shaped slit
Real-time prompt gamma monitoring in spot-scanning proton therapy using imaging through a knife-edge-shaped slit
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DOI：
10.1088/0031-9155/57/2/297
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发表时间：
2012-01-21
影响因子：
3.5
通讯作者：
Beekman, Freek
中科院分区：
文献类型：
--
作者：
Bom, Victor;Joulaeizadeh, Leila;Beekman, Freek
在本文中，我们报告了蒙特卡罗模拟，通过测量瞬发伽马射线发射来研究粒子治疗中轨迹深度剖面的实时监测：评估了采用刀刃形狭缝与位置敏感伽马探测器相结合的高灵敏度成像系统。测试这一新概念的计算是针对头部大小的软件模型进行的。检测到的能量高于 1.5 MeV 的伽马射线分布与体模发射的瞬发伽马射线分布之间显示出清晰的空间相关性。在这些高能量下检测到的源自模型中核反应的中子数量很少。最重要的是，它表明，在常见的治疗条件下，可以在一个点步骤（大约 10 毫秒）期间收集足够的数据，以优于 1 毫米的 1 西格玛精度定位远端剂量边缘。这表明简单的狭缝相机具有精确实时粒子治疗调整的巨大潜力，并可能成为提高粒子治疗精度的实用方法。
In this paper we report on Monte Carlo simulations to investigate real-time monitoring of the track depth profile in particle therapy by measuring prompt gamma ray emissions: a high sensitivity imaging system employing a knife-edge-shaped slit combined with a position-sensitive gamma detector was evaluated. Calculations to test this new concept were performed for a head-sized software phantom. Clear spatial correlation is shown between the distribution of gamma rays detected with energies above 1.5 MeV and the distribution of prompt gamma rays emitted from the phantom. The number of neutrons originating from nuclear reactions in the phantom that are detected at these high energies is small. Most importantly it is shown that under common therapy conditions enough data may be collected during one spot-step (of the order of 10 ms) to locate the distal dose edge with a 1 sigma accuracy of better than 1 mm. This indicates that simple slit cameras have high potential for accurate real-time particle therapy adjustment and may become a practical way to improve particle therapy accuracy.