Target-tracking deliveries on an Elekta linac: a feasibility study
Target-tracking deliveries on an Elekta linac: a feasibility study
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Elekta 直线加速器上的目标跟踪交付：可行性研究
DOI：
10.1088/0031-9155/54/11/019
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发表时间：
2009
影响因子：
3.5
通讯作者：
Steve Webb
中科院分区：
文献类型：
--
作者：
D. Mcquaid;Mike Partridge;J. Symonds;Philip M. Evans;Steve Webb
采用模拟靶运动轨迹，通过胶片测量评估Elekta MLCi系统上的靶跟踪、强度调制输送。在固体水体模中定义了一个环形的理想化目标，该目标围绕一个危险器官，需要多个场段来照射目标并保留危险器官。将体模编程为在束眼视图中遵循可再现的2D椭圆轨迹移动，周期为10 s。静态和目标跟踪治疗计划在一个标准的Elekta Precise系列直线加速器与集成MLCi系统上进行。剂量以三种方式输送：（i）对静态体模进行静态治疗，（ii）对移动体模进行静态治疗，（iii）对移动体模进行目标跟踪治疗。通过靶点和危及器官的中心平面上的胶片测量评估输送的剂量。靶区剂量模糊通过靶区剂量的标准差进行量化，静态治疗对静态体模的标准差为2.8%，静态治疗对移动体模的标准差为7.2%，跟踪治疗对移动体模的标准差为2.6%。每个分娩病例的平均危及器官剂量分别为处方剂量的38.2%、54.0%和38.2%。因此，我们已经表明，直线加速器是能够提供目标跟踪领域与MLC的目标轨迹测试。
A target-tracking, intensity-modulated delivery on an Elekta MLCi system was assessed by film measurement with a simulated target–motion trajectory. A toroidally shaped idealized target surrounding an organ at risk necessitating multiple field segments to irradiate the target and spare the organ at risk was defined in a solid-water phantom. The phantom was programmed to move following a reproducible 2D elliptical trajectory in the beam's-eye view with a period of 10 s. Static and target-tracking treatments were planned for delivery on a standard Elekta Precise series linac with integrated MLCi system. Dose was delivered in three ways: (i) a static treatment to a static phantom, (ii) a static treatment to a moving phantom and (iii) a target-tracking treatment to a moving phantom. The dose delivered was assessed by film measurement on the central plane through the target and organ at risk. The target dose blurring was quantified by the standard deviation of the dose to the target which was evaluated as 2.8% for the static treatment to the static phantom, 7.2% for the static treatment to the moving phantom and 2.6% for the tracking treatment to the moving phantom. The mean organ-at-risk dose was 38.2%, 54.0% and 38.2% of the prescription dose for each delivery case. We have therefore shown that the linac is capable of delivering target-tracking fields with MLCs for the target trajectories tested.