鼻咽癌放疗面罩固定技术方法的探讨

Mask fixation method in radiotherapy of nasopharyngeal carcinoma

目的:探讨鼻咽癌放射治疗两种不同面罩标记法摆位误差值,以确定提高头颈部重复摆位精度的方法。方法:面罩开窗法和不开窗法各10例,按放疗处方规范摆位,每周在加速器下摄验证片1次,与定位片比较误差大小。结果:中心点在X轴上偏离值开窗法为(1.25±0.56)mm,不开窗法为(2.67±1.56)mm;中心点在Y轴上偏离值开窗法为(1.32±0.60)mm,不开窗法为(2.91±1.71)mm,两组之间差异均有统计学意义(P<0.01)。放射治疗的2、3、4周开窗法中心点在X、Y轴上偏离值均比不开窗法有不同的优势(P<0.05-P<0.01)。结论:面罩开窗标记法照射野重复性与准确性比面罩不开窗标记法有显著的提高,是提高放射治疗摆位精度的有效方法之一,具有临床推广价值。

Objective： To measure the positioning error of two mask fixation methods in radiotherapy of nasopharyngeal carcinoma （NPC）. Methods ：Ten patients with NPC were irradiated using mask fixation method with and without windowing mark. The film was taken every week and the stray value of the field center point was measured compared with that of the localization film. Results：The X- axis stray value of field center point using mask fixation method with windowing mark was （ 1.25 ±0.56 ） mm, while that without windowing mark was（2.67 ± 1.56）mm. There was a significantly statistical difference in two groups （P 〈 0.01 ）. The Y-axis stray value of field center point using mask fixation method with windowing mark was（ 1.32 ±0.60 ） mm while that without windowing mark was（2.91 ± 1.71 ） mm. There was a significantly statistical difference in two groups （P 〈 0.05 to P 〈 0.01 ）. Condusions： The reproducibility and accuracy of mask fixation method with windowing mark were better than that without windowing mark, and it is one of effective methods in order to improve the positioning precision of radiotherapy.