面颈部肿瘤影像引导精确放射治疗摆位误差的研究

Positioning errors of neck tumor accurate radiotherapy basic on image-guiding

目的:分析基于影像引导技术的面颈部肿瘤精确放疗摆位误差。方法:对79例面颈部肿瘤放疗患者行热塑网罩体位固定,前3次放疗前利用加速器机载锥形束CT行靶区部位扫描重建三维影像,与计划CT影像比对,获得两影像空间位置偏差,经影像确认后,偏差>1mm者,予以校正,以后每周1次影像引导复核。用SAS 8.1统计软件系统处理数据。结果:91.14%的患者影像引导后需要校正,影像引导复核显示头脚方向和前后方向分别为(-0.91±1.08)mm和(-0.41±1.43)mm,左右方向为(0.15±1.09)mm。结论:影像引导有助于面颈部肿瘤精确放疗靶区精度的提高;面颈部患者体位固定时要注意头的后仰与内收以及颈部的位置固定。

OBJECTIVE： To investigate the positioning errors of neck tumor accurate radiotherapy basic on image guiding. METHODS： To compare the three-dimensional images between the CT images of TPS and the reconstructed ima ges of the XVI system which dealt with the images from the cone-beam CT of the linear accelerator after scaning before the first-three radiations of the accurate radiotherapy, while the patients were positioned with the thermoplastic masks. The space errors between the two images were corrected by the accelerator. The image-guiding were repeated weekly. The data were analyzed by the SAS statistical software. RESULTS： 91.14 %of the patients with cervicaljugular turnouts were involved in the correction of the space errors of the target area affter the image-guiding before the first three radiatons of accurate radiotherapy. The space errors in the SI-orientation and fore-and-aft-orientation in the images of the the patients with cervicaljugular tumours were （- 0.91 ± 1.08） mm and （- 0. 41±1. 43） ram,which was largger slightly than that in the right-and-left orientation [（0.15±1. 09） mm]. CONCLUSIONS： The image guiding avails the alevation of the space precision of the target area in the neck accurate radiotherapy. The retroversion-adduetion of head and fixation of cervix should be paid great attenttions when the patients with cervicaljugular tumours are positioned.