【摘要】 目的:讨论使用模拟机在鼻咽癌调强放疗中进行位置验证的方法。方法:比较50例接受调强放疗的鼻咽癌患者的数字重建影像(DRR)和模拟机图像,选择骨性标志作为参考点,测量出患者在前后、左右、头脚三个方向的位置偏移量,对位置偏移≥2mm的患者进行调整。在治疗之前,利用EPID进行适时的位置验证。结果:在模拟机室进行位置验证时,位置需要进行调整的患者数为34例(68%,34/50),只有一个方向需要移动的患者数共有23例(46%),有两个方向需要移动的患者数有8例(16%),头脚、前后、左右三个方向都需要移动的患者数有3例(6%)。头脚、前后和左右三个方向需要调整的患者数分别为27例、14例和7例。结论:在模拟机室进行治疗前的位置验证可以帮助我们减小摆位误差,避免发生摆位差错,使鼻咽癌调强放疗的摆位误差控制在可接受的范围内。更多还原

【Abstract】 Purpose: To discuss how to use simulator to verify and analysis the patients’ positions in IMRT for NPC. Methods: Fifty NPC patients treated with intensity modulation radiation therapy (IMRT) were studied. DRRs and simulation images of each patient were compared using Vision6.1 software,and displacements in antero-posterior (A-P),cranio-caudal (C-C) and medio-lateral(M-L) directions were calculated. Patients’ positions were adjusted when the displacement ≧2mm. The EPID was also used to verify the setup errors on-line in the irradiation. Results: 34(68%) patients’ positions needed to be adjusted,14 of them need a A-P adjustment,27 of them need a C-C adjustment,and 7 of them need a M-L adjustment . 23(46%) patients’ positions needed to be adjusted in only one direction,8(16%) patients’ positions needed to be adjusted in two directions,and 3(6%) patients’ positions needed to be adjusted in all the three directions. Conclusions: The patient position verification in simulator room can help us not only reduce the setup errors,it also can help us avoid mistakes in positioning. The setup error in IMTR for NPC is acceptable.更多还原