论文标题
测量呼吸诱导的食道运动及其剂量计
Measuring breathing induced oesophageal motion and its dosimetric impact
论文作者
论文摘要
立体定向的身体辐射疗法可以准确，准确的剂量递送。治疗期间的器官运动承受未发现的高剂量健康组织暴露的风险。食管是非常容易受到高剂量的器官。它在CT和长方形形状上的低对比度使运动估计变得困难。我们通过现代算法来解决这个问题，以测量食管运动素的方面，并估计运动相关的剂量影响。使用可变形的图像注册和11个内部和5个公共数据集测量食道运动。将3DCT轮廓轮廓的当前临床实践与及时解析的4DCT轮廓进行了比较。通过分析4D剂量分布中每个体素的轨迹来估算运动的剂量影响。最后，建立了器官运动模型，可以更轻松地进行患者的比较。运动分析显示，平均绝对最大运动振幅为4.55 +/- 1.81毫米，左右，5.29 +/- 2.67 mm前后杆和10.78 +/- 5.30毫米优势。队列之间的运动有显着差异。在大约50％的案件中，剂量法经过标准违反了。在3DCT上产生的轮廓没有覆盖14％的器官呼吸周期，而3D轮廓比所有4D轮廓的结合小约38％。运动模型表明，最大运动不限于器官的下部。我们的结果表明，运动幅度幅度高于文献中大多数报道的值，并且该运动在患者中是非常异质的。因此，应在轮廓和计划中考虑个人运动信息。
Stereotactic body radiation therapy allows for a precise and accurate dose delivery. Organ motion during treatment bears the risk of undetected high dose healthy tissue exposure. An organ very susceptible to high dose is the oesophagus. Its low contrast on CT and the oblong shape renders motion estimation difficult. We tackle this issue by modern algorithms to measure the oesophageal motion voxel-wise and to estimate motion related dosimetric impact. Oesophageal motion was measured using deformable image registration and 4DCT of 11 internal and 5 public datasets. Current clinical practice of contouring the organ on 3DCT was compared to timely resolved 4DCT contours. The dosimetric impact of the motion was estimated by analysing the trajectory of each voxel in the 4D dose distribution. Finally an organ motion model was built, allowing for easier patient-wise comparisons. Motion analysis showed mean absolute maximal motion amplitudes of 4.55 +/- 1.81 mm left-right, 5.29 +/- 2.67 mm anterior-posterior and 10.78 +/- 5.30 mm superior-inferior. Motion between the cohorts differed significantly. In around 50 % of the cases the dosimetric passing criteria was violated. Contours created on 3DCT did not cover 14 % of the organ for 50 % of the respiratory cycle and the 3D contour is around 38 % smaller than the union of all 4D contours. The motion model revealed that the maximal motion is not limited to the lower part of the organ. Our results showed motion amplitudes higher than most reported values in the literature and that motion is very heterogeneous across patients. Therefore, individual motion information should be considered in contouring and planning.
