Analysis of Position Errors Between Two Fixed Methods of Straight Neck
Position and Neck Hyperextension Position in Head and Neck Cancer
Radiotherapies
Abstract：Objective To explore the difference between two different fixation methods in improving the
accuracy of radiotherapy. Methods All the patients were treated with supine position, fixation of patient’s
head, neck and shoulder with thermoplastic films and vacuum bags, the same head, neck and shoulder
intensity positioning treatment plate, three-dimensional conformal radiotherapy and IMRT (Intensity
Modulated Radiation Therapy). Patients in Control Group were treated in straight neck position; while,
patients in Study Group were treated in neck hyperextension position. Deviations in every direction was
acquired through registration of EPID (Electronic Portal Imaging System) and DRR (Digitally Reconstructed
Radiograph) to calculate the setup errors and outer margins respectively. Results Setup errors in the left
and right, head and feet, dorsal and ventral direction of Control Group and Study Group were (0.09±0.07),
(0.23±0.19), (0.19±0.21) mm and (0.06±0.08), (0.15±0.12), (0.12±0.12) mm respectively; the
outer margins of Control Group and Study Group were 0.26, 0.49, 0.50 mm and 0.24, 0.33, 0.40 mm
respectively. The linear errors of two groups in the 3 directions were 0.075, 0.032, 0.047 respectively.
Conclusion When other conditions were the same, the fixation effect of neck hyperextension position
was superior than that of straight neck position; the outer margin of Study Group was smaller than that of
Control Group, indicated that adoption of the neck hyperextension position as the radiotherapy location
was relatively more precise. And it was recommended to adopt the neck hyperextension position fixation
method for patients with a good degree of coordination in case of abundant time.
钟强，陈紫红，谢金莲，余海
坤，高建全，朱锦贤. 头颈部肿瘤放疗颈直位与过伸位两种固定方法摆位误差分析[J]. 中国医疗设备, 2016, 31(9): 113-115.
ZHONG Qiang, CHEN Zi-hong,
XIE Jin-lian, YU Hai-kun,
GAO Jian-quan, ZHU Jin-xian. Analysis of Position Errors Between Two Fixed Methods of Straight Neck
Position and Neck Hyperextension Position in Head and Neck Cancer
Radiotherapies. China Medical Devices, 2016, 31(9): 113-115.
