论文部分内容阅读
目的:比较研究两种不同固定方式对胸中段食管癌患者放射治疗时摆位误差的影响效果,并对临床靶区(Clinical Target Volume,CTV)到计划靶区(Planning Target Volume,PTV)外放间距进行初步探讨,为胸中段食管癌患者放疗选用合适固定方法提供参考。方法:选取2012年1月至2013年1月在我院应用瓦里安TrueBeam治疗系统治疗的胸中段食管癌病者60例,其中32例用S型头颈肩面膜固定,28例采用真空袋固定。所有患者治疗期间,每周行锥形束CT(Cone-Beam Computed Tomography,CBCT)扫描一次,将CBCT图像和原计划CT图像进行配准得出X、Y、Z轴方向的线性摆位误差,分析摆位误差及其分布规律,推算出CTV到PTV的外放边界值。结果:采用真空袋固定的摆位误差在X轴(左右方向)、Y轴(头脚方向,)、Z轴(前后方向)上分别为(1.9±1.7)mm,(2.5±2.4)mm,(2.6±2.5)mm,CTV-PTV的外放边界分别为5.9mm、7.9mm、8.3mm;而采用头颈肩面膜固定的各方向误差范围都较真空袋固定的小,X轴(1.9±1.6)mm,Y轴(2.4±1.7)mm,Z轴(1.5±1.5)mm,CTV-PTV的外放边界3个方向分别为5.9mm、7.1mm、4.7mm。两组X轴、Y轴方向移位范围无明显差异(P>0.05),Z轴有明显差异(P<0.05)。结论:对胸中段食管癌患者放疗摆位,使用头颈肩面膜固定技术稳定性比真空袋好,摆位误差明显减少,放疗精度提高。
OBJECTIVE: To compare the effects of two different fixation modalities on the setting errors of radiotherapy for patients with esophageal cancer of the middle breast, and to compare the clinical target volume (CTV) with planning target volume (PTV) Pitch for a preliminary discussion for the mid-thoracic esophageal cancer patients with radiotherapy using appropriate fixation methods provide a reference. Methods: Sixty patients with thoracic esophageal cancer who were treated with Varian TrueBeam in our hospital from January 2012 to January 2013 were selected. Of them, 32 cases were fixed with S type head and neck shoulder mask and 28 cases were fixed with vacuum bag . All patients underwent weekly CT scan with Cone Beam Computed Tomography (CBCT) to register the CBCT images and the original planned CT images to obtain the linear misposition errors in X, Y and Z directions. Analysis of the setup error and its distribution law, extrapolation boundary value of CTV to PTV is deduced. Results: The setup errors with vacuum bag fixation were (1.9 ± 1.7) mm and (2.5 ± 2.4) mm in the X axis (left and right directions), Y axis (head and foot direction) and Z axis (2.6 ± 2.5) mm, respectively. The external margin of CTV-PTV was 5.9mm, 7.9mm and 8.3mm, respectively. ) mm, Y axis (2.4 ± 1.7) mm, and Z axis (1.5 ± 1.5) mm respectively. The three directions of the CTV-PTV are: 5.9mm, 7.1mm and 4.7mm. There was no significant difference between the two groups (P> 0.05) and the Z axis (P <0.05). Conclusions: The stability of radiotherapy for patients with esophageal cancer in the middle thoracic esophagus is better than that of the vacuum bag using the fixation of head and neck shoulder and shoulder, and the error of setting is obviously reduced and the radiotherapy accuracy is improved.