The precision of respiratory-gated delivery of synchrotron-based pulsed beam proton therapy
The precision of respiratory-gated delivery of synchrotron-based pulsed beam proton therapy
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DOI：
10.1088/0031-9155/55/24/016
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发表时间：
2010-12-21
影响因子：
3.5
通讯作者：
Mohan, Radhe
中科院分区：
文献类型：
--
作者：
Tsunashima, Yoshikazu;Vedam, Sastry;Mohan, Radhe
基于同步加速器的质子治疗系统以低重复率脉冲束递送模式操作。与基于回旋加速器的光束传输不同，不能保证同步加速器光束可以在回旋门控模式下有效或精确地传输。为了评估门控同步加速器治疗的性能，我们使用真实的患者呼吸信号模拟了基于同步加速器的闪烁门控模式中的质子束输送。模拟中使用的参数是呼吸运动轨迹（来自24名患者的70条轨迹）、呼吸门控水平（呼气阶段的10%、20%和30%占空比）和同步加速器磁体激励循环（T（cyc））（固定T（cyc）模式：2.7、3.0-6.0 s和每个患者呼吸循环，以及可变T（cyc）模式）。根据质子束输送的呼吸轨迹计算模拟。在较短的固定T（cyc）（4 s）和可变T（cyc）模式下，在呼吸周期的呼气末阶段，质子束的输送并不一致。然而，我们发现，较长的和可变的T（循环）的操作模式提供质子束更精确地在不规则的呼吸。
A synchrotron-based proton therapy system operates in a low repetition rate pulsed beam delivery mode. Unlike cyclotron-based beam delivery, there is no guarantee that a synchrotron beam can be delivered effectively or precisely under the respiratory-gated mode. To evaluate the performance of gated synchrotron treatment, we simulated proton beam delivery in the synchrotron-based respiratory-gated mode using realistic patient breathing signals. Parameters used in the simulation were respiratory motion traces (70 traces from 24 patients), respiratory gate levels (10%, 20% and 30% duty cycles at the exhalation phase) and synchrotron magnet excitation cycles (T(cyc)) (fixed T(cyc) mode: 2.7, 3.0-6.0 s and each patient breathing cycle, and variable T(cyc) mode). The simulations were computed according to the breathing trace in which the proton beams were delivered. In the shorter fixed T(cyc) (4 s) and the variable T(cyc) mode, the proton beams were not consistently delivered during the end-expiration phase of the respiratory cycle. However we found that the longer and variable T(cyc) operation modes delivered proton beams more precisely during irregular breathing.