Yaremko Brian P, Guerrero Thomas M, McAleer Mary F, Bucci M Kara, Noyola-Martinez Josue, Nguyen Linda T, Balter Peter A, Guerra Rudy, Komaki Ritsuko, Liao Zhongxing
Division of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
Int J Radiat Oncol Biol Phys. 2008 Jan 1;70(1):145-53. doi: 10.1016/j.ijrobp.2007.05.031. Epub 2007 Sep 12.
To investigate the motion characteristics of distal esophagus cancer primary tumors using four-dimensional computed tomography (4D CT).
Thirty-one consecutive patients treated for esophagus cancer who received respiratory-gated 4D CT imaging for treatment planning were selected. Deformable image registration was used to map the full expiratory motion gross tumor volume (GTV) to the full-inspiratory CT image, allowing quantitative assessment of each voxel's displacement. These displacements were correlated with patient tumor and respiratory characteristics.
The mean (SE) tidal volume was 608 (73) mL. The mean GTV volume was 64.3 (10.7) mL on expiration and 64.1 (10.7) mL on inspiration (no significant difference). The mean tumor motion in the x-direction was 0.13 (0.006) cm (average of absolute values), in the y-direction 0.23 (0.01) cm (anteriorly), and in the z-direction 0.71 (0.02) cm (inferiorly). Tumor motion correlated with tidal volume. Comparison of tumor motion above vs. below the diaphragm was significant for the average net displacement (p = 0.014), motion below the diaphragm was greater than above. From the cumulative distribution 95% of the tumors moved less than 0.80 cm radially and 1.75 cm inferiorly.
Primary esophagus tumor motion was evaluated with 4D CT. According to the results of this study, when 4D CT is not available, a radial margin of 0.8 cm and axial margin of +/-1.8 cm would provide tumor motion coverage for 95% of the cases in our study population.
使用四维计算机断层扫描（4D CT）研究远端食管癌原发肿瘤的运动特征。
选取31例连续接受食管癌治疗且为治疗计划进行呼吸门控4D CT成像的患者。采用可变形图像配准技术将全呼气时的大体肿瘤体积（GTV）映射到全吸气CT图像上，以便对每个体素的位移进行定量评估。这些位移与患者的肿瘤及呼吸特征相关。
平均（标准误）潮气量为608（73）mL。呼气时平均GTV体积为64.3（10.7）mL，吸气时为64.1（10.7）mL（无显著差异）。肿瘤在x方向的平均运动为0.13（0.006）cm（绝对值平均值），y方向为0.23（0.01）cm（向前），z方向为0.71（0.02）cm（向下）。肿瘤运动与潮气量相关。膈上与膈下肿瘤运动的平均净位移比较有显著差异（p = 0.014），膈下运动大于膈上。从累积分布来看，95%的肿瘤径向移动小于0.80 cm，向下移动小于1.75 cm。
采用4D CT对原发性食管肿瘤运动进行了评估。根据本研究结果，当无法获得4D CT时，0.8 cm的径向边界和±1.8 cm的轴向边界可为我们研究人群中95%的病例提供肿瘤运动覆盖范围。
