Commissioning of the discrete spot scanning proton beam delivery system at the University of Texas MD Anderson Cancer Center, Proton Therapy Center, Houston
Commissioning of the discrete spot scanning proton beam delivery system at the University of Texas MD Anderson Cancer Center, Proton Therapy Center, Houston
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DOI：
10.1118/1.3259742
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发表时间：
2010-01-01
期刊：
影响因子：
3.8
通讯作者：
Zhu, X. Ronald
中科院分区：
文献类型：
--
作者：
Gillin, Michael T.;Sahoo, Narayan;Zhu, X. Ronald
目的：描述休斯顿质子治疗中心（PTC-H）离散点扫描质子束临床调试的总结。方法：离散点扫描系统由递送系统（日立ProBeat）、电子病历（Mosaiq V 1.5）和治疗计划系统（TPS） （Eclipse V 8.1）组成。离散质子铅笔束（点）用于在质子远端范围从4.0到30.6 g/cm(2)和30 X 30 cm(2)的最大扫描区域内逐点、逐层沉积剂量。选择任意选择的基准校准条件来定义监测单元（mu）。利用放射性致色膜和离子室测量了空气中的光斑位置、光斑大小、深度剂量曲线和不同能量的质子束在水中的分布，并研究了剂量监测器的线性度。除了剂量测量和TPS建模之外，还在测试信息流和治疗中断后输送系统的恢复方面花费了大量精力。结果：调整了主剂量监测仪，在特定参考条件下，按照IAEA TRS 398方案，在监测室中收集单个MU对应的特定电荷量。剂量监测器的校准方法是基于每μ m的绝对剂量，相当于每粒子的绝对剂量，这是其他扫描束机构使用的方法。空气中光斑尺寸的半最大全宽度从221.8 MeV时的约1.2 cm到72.5 MeV时的3.4 cm不等。在4.0-30.6厘米的范围内，测量的与要求的90%深度剂量在1毫米范围内一致。光束传递联锁按预期执行，保证计划剂量的安全和准确传递。结论：作为临床调试程序的一部分，离散点扫描质子束的剂量学参数已经测量，并且发现该机器以安全的方式运行，使其适合患者治疗。(C) 2010年美国医学物理学家协会。(DOI: 10.1118/1.3259742)
Purpose: To describe a summary of the clinical commissioning of the discrete spot scanning proton beam at the Proton Therapy Center, Houston (PTC-H).Methods: Discrete spot scanning system is composed of a delivery system (Hitachi ProBeat), an electronic medical record (Mosaiq V 1.5), and a treatment planning system (TPS) (Eclipse V 8.1). Discrete proton pencil beams (spots) are used to deposit dose spot by spot and layer by layer for the proton distal ranges spanning from 4.0 to 30.6 g/cm(2) and over a maximum scan area at the iso-center of 30 X 30 cm(2). An arbitrarily chosen reference calibration condition has been selected to define the monitor units (MUs). Using radiochromic film and ion chambers, the authors have measured spot positions, the spot sizes in air, depth dose curves, and profiles for proton beams with various energies in water, and studied the linearity of the dose monitors. In addition to dosimetric measurements and TPS modeling, significant efforts were spent in testing information flow and recovery of the delivery system from treatment interruptions.Results: The main dose monitors have been adjusted such that a specific amount of charge is collected in the monitor chamber corresponding to a single MU, following the IAEA TRS 398 protocol under a specific reference condition. The dose monitor calibration method is based on the absolute dose per MU, which is equivalent to the absolute dose per particle, the approach used by other scanning beam institutions. The full width at half maximum for the spot size in air varies from approximately 1.2 cm for 221.8 MeV to 3.4 cm for 72.5 MeV. The measured versus requested 90% depth dose in water agrees to within 1 mm over ranges of 4.0-30.6 cm. The beam delivery interlocks perform as expected, guarantying the safe and accurate delivery of the planned dose.Conclusions: The dosimetric parameters of the discrete spot scanning proton beam have been measured as part of the clinical commissioning program, and the machine is found to function in a safe manner, making it suitable for patient treatment. (C) 2010 American Association of Physicists in Medicine. [DOI: 10.1118/1.3259742]