Technical and dosimetric aspects of respiratory gating using a pressure-sensor motion monitoring system
Technical and dosimetric aspects of respiratory gating using a pressure-sensor motion monitoring system
复制标题
DOI：
10.1118/1.2147743
复制
发表时间：
2006-01-01
期刊：
影响因子：
3.8
通讯作者：
Gore, E
中科院分区：
文献类型：
--
作者：
Li, XA;Stepaniak, C;Gore, E
这项工作介绍了一种门控技术，使用4DCT确定门控参数和计划门控治疗，并采用西门子直线加速器提供门控治疗。由于技术不兼容，4DCT扫描仪（LightSpeed，GE）和Siemens加速器需要两种不同的运动监测系统。运动监测系统（AZ-773 V，Anzai Med.）用于门控输送的压力传感器利用压力传感器来真实的检测外部呼吸运动（压力变化）。用于4DCT扫描仪（LightSpeed，GE）的另一系统（RPM，Varian）基于红外摄像机来检测外部标记的运动。这两个运动监测系统（RPM和Anzai系统）被发现相互关联。发现门控输送（占空比为25%或50%）的深度剂量和剖面测量值与非门控输送的深度剂量和剖面测量值在1.0%范围内一致，表明门控并未显著改变射束特性。测量还验证MU线性度和光束输出保持不变（在0.3%内）。开发了一种使用4DCT规划门控治疗的实用方法。相位或幅度选通的占空比可以基于4DCT确定，同时考虑设置误差和传输效率。涉及整个门控过程（成像、计划和输送）的闭环测量表明，测得的等剂量分布与预期分布一致，验证了门控技术的准确性和可靠性。基于这些观察结果，我们得出结论，在这项工作中介绍的门控技术，集成西门子直线加速器和Anzai压力传感器设备与GE/Varian RPM 4DCT，是可靠和有效的，它可以用于临床考虑放射治疗期间的呼吸运动。(c)2006年美国医学物理学家协会。
This work introduces a gating technique that uses 4DCT to determine gating parameters and to plan gated treatment, and employs a Siemens linear accelerator to deliver the gated treatment. Because of technology incompatibility, the 4DCT scanner (LightSpeed, GE) and the Siemens accelerator require two different motion-monitoring systems. The motion monitoring system (AZ-773V, Anzai Med.) used for the gated delivery utilizes a pressure sensor to detect the external respiratory motion (pressure change) in real time. Another system (RPM, Varian) used for the 4DCT scanner (LightSpeed, GE) is based on an infrared camera to detect motion of external markers. These two motion monitoring systems (RPM and Anzai systems) were found to correlate well with each other. The depth doses and profile measured for gated delivery (with a duty cycle of 25% or 50%) were found to agree within 1.0% with those measured for ungated delivery, indicating that gating did not significantly alter beam characteristics. The measurement verified also that the MU linearity and beam output remained unchanged (within 0.3%). A practical method of using 4DCT to plan a gated treatment was developed. The duty cycle for either phase or amplitude gating can be determined based on 4DCT with consideration of set-up error and delivery efficiency. The close-loop measurement involving the entire gating process (imaging, planning, and delivery) showed that the measured isodose distributions agreed with those intended, validating the accuracy and reliability of the gating technique. Based these observations, we conclude that the gating technique introduced in this work, integrating Siemens linear accelerator and Anzai pressure sensor device with GE/Varian RPM 4DCT, is reliable and effective, and it can be used clinically to account for respiratory motion during radiation therapy. (c) 2006 American Association of Physicists in Medicine.