四维CT测量平静呼吸下原发胸段食管肿瘤运动的初步研究

The analysis of thoracic esophageal tumor mobility during normal respiration with four-dimensional computed tomography

目的采用四维CT（4DCT）探讨平静呼吸状态下原发食管肿瘤的运动特征。方法16例原发食管癌患者在平静呼吸体位下采用4DCT采集原发灶运动信息，并在每个患者10套图像上勾画大体肿瘤体积（GTV1～GTV10），测量并记录每个中心点坐标，计算每个中心点在不同呼吸时相的移动距离，分析胸部各段食管肿瘤运动特征。结果呼气相和吸气相双肺、食管癌原发灶体积分别为2993．50cm3和3362．12cm3（t=12．36，P=0．000）、35．00cm3和34．84cm3（t=-0．61，P=0．546）。食管癌靶区中心在左右、前后、头脚方向总移动峰值分别为0．65、0．55、2．03mm（F=41．14，P=0．000），胸上段的分别为0．50、0．48、1．23mm（F=5．45，P=0．017），胸中段的为0．68、0．62、1．97mm（F=27．74，P=0．000），胸下段的为0．72、0．38、3．05mm（F=15．61，P=0．000）。结论胸段食管肿瘤左右、前后方向运动幅度较小，头脚方向运动幅度较大，不同段病灶运动也有所不同。

Objective To investigate the motion characteristics of primary thoracic esophageal carcinoma with four-dimensional computed tomography （4DCT）. Methods Sixteen patients with primary thoracic esophageal carcinoma received respiratory gated 4DCT imaging, mapping the GTV1-GTV10 on every patient＇s each subsequent CT image of 10 images in the full-respiratory phase, and measuring the displacement of each centre of GTV. These displacements and directions were analyzed on different segments of esophagus. Results The mean total lung volume and GTV volume was 2993.5 cm3 , 35.00 cm3 and 3362. 12 cm3 , 34. 84 cm3 respectively on end-expiration and end-inspiration phases （ t = 12. 36, P = 0. 000 and t = -0. 61 ,P =0. 546）. The total mean peak to peak displacement of GTV were 0. 65 mm,0. 55 mm, and 2. 03 mm in x, y-and z-axis direction, respectively （F =41.14,P =0. 000）. The motion in x-axis, y- axis and z-axis were 0. 50 mm ,0. 48 mm, 1.23 mm in the upper segment （ F = 5.45 ,P = 0. 017 ） , 0. 68 mm, 0. 62 mm, 1.97 mm in the middle segment （ F = 27. 74, P = 0. 000）, 0.72 mm,0. 38 mm, 3.05 mm in the lower segment, respectively （ F = 15.61, P = 0. 000）. Conclusions The displacement of tumor in z axis is more notable than x-, y-axis in thoracic esophageal carcinoma. The displacement of tumor in x-,y-and z-axis is different in different segment of thoracic esophageal carcinoma.