胸部肿瘤放疗患者双手放置方式对摆位误差的影响

Influence of Arm Position of Patients Receiving Radiotherapy for Chest Tumors on Setup Error

目的探讨胸部肿瘤患者放疗中双手放置方式对摆位误差的影响。方法回顾性分析2013年1月—2014年6月浙江省肿瘤医院放疗科接受调强放疗的40例胸部肿瘤患者的临床资料。根据放疗时双手放置方式的不同分为甲组(双手抱肘置于额头上,n=21)和乙组(双手置于身体两侧,n=19)。每例患者行CT模拟定位,勾画肿瘤靶区和累及器官,制定放疗计划。治疗第1周,每次治疗前行机载锥形束CT(CBCT)扫描,以后每周扫描1次,共扫描9次。对两组患者肿瘤靶区的平移摆位误差进行测量。结果甲组患者左右方向、上下方向摆位误差小于乙组(P<0.05);两组患者前后方向摆位误差比较,差异无统计学意义(P>0.05)。甲组患者左右方向、上下方向校准频率小于乙组(P<0.05);两组患者前后方向校准频率比较,差异无统计学意义(P>0.05)。结论胸部肿瘤放疗患者双手放置方式对摆位误差有影响,双手抱肘置于额头上的方式引起的摆位误差较小。如果患者因各种原因无法采用双手抱肘置于额头上的方式而采用双手置于身体两侧的方式时,应对目前所使用的体架以及热塑膜进行改进以利于降低摆位误差。

Objective To investigate the influences of two kinds of arm positions（ on the forehead with hands holding the elbow,or on both body sides） of patients receiving radiotherapy for chest tumors on setup error. Methods A retrospective analysis was carried out on the clinical data of 40 cases of patients with chest tumor,who were treated with intensity modulated radiotherapy in the Department of Radiation Physics of Zhejiang Cancer Hospital from January 2013 to June 2014. The patients were divided into two groups according to the position of the arms. Patients in group A（ n = 21） put their arms on the forehead with hands holding the elbow,while patients in group B（ n = 19） put their hands on both body sides. Each patient was given CT simulation scan to draw target outline and involved organs and make radiotherapy plans. In the first week of treatment,CBCT was performed before each time of treatment, then once every week for 9 weeks. The translational setup errors of the target radiotherapy sections of the two groups were measured. Results Group A had smaller setup errors at the left- right direction and the ventral- dorsal direction than group B（ P〈0. 05）; the two groups were not significantly different in the setup errors at the head- to- toe direction（ P〉0. 05）. Group A had lower calibration frequency at the left- right direction and at the ventral-dorsal direction than group B（ P〈0. 05）; the two groups were not significantly different in the calibration frequency at the head- to- toe direction（ P〉0. 05）. Conclusion The arm position of patients receiving radiotherapy for chest tumor has influence on setup errors. Patients have smaller setup error when putting their arms on the forehead with hands holding the elbow. If the patient can＇t do this posture due to various reasons and the position of hands on both body sides is used instead,the current frame and thermoplastic membrane should be improved to reduce the setup error of treatment.