口含器与头颈部肿瘤放射治疗中摆位误差的相关性研究

目的利用螺旋断层放疗系统获取的摆位数据探讨口含器对头颈部肿瘤的摆位误差的影响，为预防及减少病人头颈部肿瘤放射治疗不良反应提供参考。方法选择放射治疗的头颈部肿瘤病人25例，分为观察组（13例）和对照组（12例）。观察组采用热塑膜+口含器固定，对照组采用热塑膜固定。利用MVCT影像分析2组病人在X轴、Y轴、Z轴和ROLL四个方向的摆位误差。结果观察组在X轴和ROLL方向的摆位误差明显小于对照组（P < 0.01），Z轴方向的摆位误差高于对照组（P < 0.05），2组Y轴方向的摆位误差差异无统计学意义（P>0.05）。在X轴和Y轴方向上摆位误差在0~2 mm，观察组在X轴和Y轴方向的低误差分布均高于对照组（P < 0.01和P < 0.05）；Z轴摆位误差主要集中在>2.1 mm，观察组高误差分布明显高于对照组（P < 0.01）；ROLL方向摆位误差主要集中在0~1.0 mm，观察组低误差分布明显高于对照组（P < 0.01）。结论口含器可在一定程度上减少摆位误差，对于无明显张口困难、耐受性较好的病人，可以考虑使用口含器，从而减少头颈部肿瘤放射治疗相关不良反应。

Study on the correlation between mouthplate and positioning error in radiotherapy for head and neck tumor

ObjectiveTo explore the effect of mouthplate on the positioning error of head and neck tumor by using the positioning data obtained from helical tomotherapy system, to provide reference for preventing and reducing the adverse reactions of radiotherapy for head and neck tumor.MethodsTwenty-five patients with head and neck tumor were selected and divided into observation group (13 cases) and control group (12 cases).The observation group was fixed with thermoplastic film and mouthplate, and the control group was fixed with thermoplastic film.MVCT images were used to analyze the positioning errors of the two groups in X-axis, Y-axis, Z-axis and ROLL direction.ResultsThe positioning error in X-axis and ROLL direction in observation group was significantly less than that in control group (P < 0.01), and the positioning error in Z-axis was higher than that in control group (P < 0.05).There was no significant difference in positioning error in Y-axis between the two groups (P>0.05).In the X-axis and Y-axis, the positioning error was 0-2 mm, and the low error distribution in X-axis and Y-axis in observation group was higher than that in control group (P < 0.01 and P < 0.05).The positioning error in Z-axis mainly distributed in the range of >2.1 mm, and the high error distribution in observation group was significantly higher than that in control group (P < 0.01).The positioning error in ROLL direction mainly distributed in the range of 0-1.0 mm, and the low error distribution in observation group was significantly higher than that in control group (P < 0.01).ConclusionsThe mouthplate can reduce the positioning error to a certain extent.For patients with no obvious difficulty in opening mouth and good tolerance, mouthplate can be used to reduce the radiotherapy-related adverse reactions in head and neck tumor patient.