主动呼吸控制系统结合适形放射治疗非小细胞肺癌临床剂量学分析

Application of Active Breathing Control System in Radiotherapy of Non-small Cell Lung Cancer: a Research of Dosimetry

目的：探讨主动呼吸控制系统（ABC）结合适形放射治疗应用在非小细胞肺癌（NSCLC）中的可行性。方法：2005年2月-2007年10月，19例Ⅱ-Ⅳ期未能手术的非小细胞肺癌进入研究。入组患者分别在ABC控制下和自由呼吸状态下行CT扫描，并在两个重建图像中按同样条件进行计划设计，通过剂量体积直方图（dose volume histogram，DVH）评价两个计划的GTV、CTV、PTV、双肺体积（Volumelung）、双肺V20和双肺平均剂量（MDL）。结果：在NSCLC放疗过程中使用ABC技术，GTV、CTV、PTV较常规治疗有一定缩小，双肺V20和双肺平均剂量均低于常规治疗，有显著差畀。结论：对于呼吸动度较大的NSCLC，ABC是一种简便、可行的图像引导放射治疗技术。

Objective：To evaluate the feasibility of using active breathing control system in radiotherapy of non-small cell lung cancer. Methods： 19 patients with inoperable no-small-cell lung cancer （NSCLC） were evaluated from Feb 2005 to Oct 2007. For each patient, two series CT scans were obtained with free breathing （FB） and controlled by ABC system during simulation, re spectively. The breath hold pattern was deep inspiration breath hold （DIBH） with breath holding at 80% inspiration volume of the maximum. Two plans of two series CT scans were designed at the same condition. GTV,CTV,PTV,Volumelung ,V20 and MDL of two plans were evaluated by DVH. Results： Significant difference were observed between GTV,CTV,PTV,Volumelung ,V20 and MDL of two plans, P〈0.01. Conclusion： ABC is a simple and convenient IGRT technology, especially for those which have significant respiratory-induced tumor motion.