鼻咽癌调强放疗颈部摆位误差的研究

目的：利用锥形束CT （CBCT）分析鼻咽癌调强放疗中颈部的摆位误差.方法：有颈部淋巴结转移并接受调强放射治疗的鼻咽癌共12例.患者采用颈肩面罩加个体化真空垫头枕固定,所有患者均行CT模拟.每周治疗前拍1次CBCT图像,每位患者接受6次CBCT.相对于计划CT,分别分析整个靶区和颈部在头脚、垂直、左右方向上的摆位误差.结果：整体的摆位误分别为0.58±1.82mm（头脚方向）,1.85±1.76mm（垂直方向）,0.76±2.13mm（左右方向）；颈部的摆位误差分别为0.68±1.93mm（头脚方向）；2.23±1.89mm（垂直方向）；1.03±2.34mm（左右方向）.结论：颈部摆位误差与整体摆位误差不同.

The Study of Setup errors of the Neck in the process of intensity modulation radiation therapy of nasopharyngeal carcinoma

Objective： To evaluate set up errors of the neck by cone beam CT in the process of intensity modulation radiated therapy of nasopharyngeal carcinoma. Methods： Twelve patients of neck metastasis nasopharyngeal carcinoma were selected. All the patients were immobilized by head - neck shoulder thermoplastic mask and vacuum pillows. All patients underwent CT simulation. The cone beam CT images were scanned every week before treatment. Each patient received 6 times CBCT. To analyze the setup errors in head and feet, vertical, left and fight direction about the entire target area and neck relative to their position in the planning CT. Results The setup error of the entire target area was 0. 58 ± 1.82mm, 1.85 ± 1.76mm, 0. 76 ± 2. 13mm respectively in head and feet,vertical, left and right direction; The setup error of the neck was 0. 68 ±1.93mm, 2. 23 ± 1.89ram, 1.03 ± 2. 34mm respectively. Conclusion The setup error between the entire target area and the neck is different.