瓦里安呼吸门控系统在射波刀治疗肺部肿瘤中的应用

发布时间：2018-06-19 09:23

  本文选题：肺癌 + 射波刀　； 参考：《清华大学》2015年硕士论文

【摘要】：呼吸运动是影响肺部肿瘤立体定向放射治疗过程中的重要因素,因为肿瘤的内靶区(ITV)的确定较为困难。同步动态追踪技术(Synchrony)是射波刀治疗肺部肿瘤最大的优势,它是通过B超或CT引导下穿刺,将圆柱形金标(Fiducials)植入到在患者病灶附近或周边,在治疗开始时,患者穿着同步呼吸追踪背心,获取患者在整个呼吸周期的波形,同时拍摄一系列X射线肺部影像片,获得不同呼吸时刻金标的位置,建立金标位置和呼吸波形二者的相互关系,指导机械手臂控制射线束随患者的呼吸节奏运动,这样就实现了射线实时追踪肿瘤。这项技术使放疗医生在勾画靶区的过程不必考虑肿瘤随呼吸运动的影响,减少勾画靶区的范围,一定程度上缩小了肿瘤周边正常组织的受照范围。但是在临床实践中,总有部分患者自身原因不能接受金标植入手术,对于这部分患者,最好用4D-CT定位扫描方法确定肿瘤在呼吸过程中的运动范围,找到肿瘤内靶区(ITV)的边界,治疗时通常采取脊柱追踪(Xsight-Spine)技术。但4D-CT扫描技术机器配置相对较高,扫描过程较普通定位CT扫描较为复杂,且患者在接受4D-CT扫描时受照剂量较普通CT扫描剂量大。鉴于此,本研究选取射波刀治疗的37例肺部肿瘤患者,通过瓦里安呼吸门控实时位置管理系统(RPM)获得患者实时的监测呼吸时相,观察其呼吸波形来训练其呼气、吸气末屏气,并扫描其呼气、吸气末屏气状态的CT图像序列,分别找到两个图像序列中肿瘤中心的三维坐标,分别与同一患者4D-CT扫描得到的呼气、吸气末图像序列中的肿瘤中心三维坐标作比较,分析得出每位患者每个病灶的三维坐标差异,为临床工作提供依据。研究结果证明,通过使用瓦里安RPM系统监测呼吸波形采集到的呼气、吸气末CT图像序列中的病灶三维坐标值与4D-CT采集的呼气、吸气末CT图像序列中的病灶三维坐标值基本一致,存在差异受以下因素影响,坐标差值随年龄增大有增大趋势,同一患者肺下部肿瘤差别最大、肺中部次之、肺上部最小。
[Abstract]:Respiratory movement is an important factor affecting the stereotactic radiotherapy of lung tumors, because the internal target area of the tumor (ITV) is difficult to determine. Synchronous dynamic tracking (Synchrony) is the greatest advantage of the radio wave knife in the treatment of lung cancer. It is inserted through a B-mode or CT guided puncture, and the cylindrical gold mark (Fiducials) is implanted in the patient. Near or around the lesion, at the beginning of the treatment, the patient wore a synchronous breathing tracking vest, acquired the patient's waveform of the entire respiratory cycle, and photographed a series of X ray radiographic images to obtain the position of the gold mark at different breaths, and set up the relationship between the position of the gold mark and the two of the respiratory waves, guiding the mechanical arm to control the ray beam. The technique enables the doctor to trace the target area without considering the effect of the tumor with the respiratory movement, reducing the scope of the target area and reducing the scope of the normal tissue around the tumor to a certain extent. However, in clinical practice, there are always some patients in clinical practice. In this part of the patients, it is best to use the 4D-CT location scanning method to determine the range of the movement of the tumor in the breathing process, to find the boundary of the target area (ITV) in the tumor, and to use the spinal tracking (Xsight-Spine) technique in the treatment. But the 4D-CT scanning technique is relatively high in the machine configuration and the scanning process is more common. The location of CT scan is more complex, and the dose of the patient in the 4D-CT scan is larger than that of the ordinary CT scan. In view of this, this study selects 37 cases of lung cancer patients treated with radio wave knife, through the real time position management system (RPM) of the Varian respiratory gated control system (RPM), to obtain the real-time monitoring of the respiratory phase of the patient, and observe its respiratory waveform to train its call Gas is breathed and breathed at the end of breath, and the CT image sequence of its expiration and breath holding state is scanned. The three-dimensional coordinates of the tumor center in the two image sequences are found respectively. The three-dimensional coordinates of the tumor centers in the exhaled and inhaled image sequences obtained by the same patient 4D-CT scan are compared respectively, and the three-dimensional coordinates of each focus of each patient are analyzed. The difference is the basis for clinical work. The results show that the three-dimensional coordinate values of the focus in the CT image sequence of the terminal RPM are basically consistent with the three-dimensional coordinates of the focus in the exhale and the end of the aspirated CT image sequence, and the differences are influenced by the following factors. The difference increased with the age increasing, the same is the biggest difference in patients with lung tumor, lung in the middle, upper lung is minimal.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R734.2
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本文编号：2039401