摘要
目的探讨负压真空垫固定双下肢法与自制泡沫脚垫固定双脚踝法固定体位方式在直肠癌IMRT中对摆位误差的影响。方法2014年选取12例直肠癌患者随机均分成A、B组，A组患者负压真空垫固定双下肢法，B组患者采用自制塑料泡沫脚垫固定双侧脚踝法。采集108人次（A、B组各54人次）治疗前后KV—CBCT图像行灰度平移误差配准，成组t检验两组患者在左右方向（x轴）、上下方向（Y轴）、前后方向（z轴）的摆位误差。结果两组患者y轴摆位误差相近[（2．13±0．64）min：（2．61±1．17）mm，P=0．399]；x轴摆位误差A组低于B组[（1．51±0．28）mm：（2．70±1．05）mm，p=0．039]，A、B组误差率分别7．41％、42．59％；z轴上A组也低于B组[（1．10±0．29）mm：（2．37±0．71）mm，P=0．002]，A、B组误差率分别1．85％、35．19％。结论直肠癌放疗摆位采用负压真空垫固定双下肢法有效避免了双下肢左右平移和内外旋转。从而减少摆位误差．比自制泡沫脚垫固定双脚踝法的精确性更高。
Objective To investigate the influence of fixation of both lower limbs with negative pressure vacuum cushion and fixation of both ankles with self-made foam mat on setup errors in radiotherapy for rectal cancer. Methods A total of 12 patients with rectal cancer were enrolled in 2014 and randomly divided into group A （using negative pressure vacuum cushion） and group B （using self-made foam mat）.An offline registration analysis was performed for the images of 108 times （A, B group of 54 times） of kilovohage cone-beam CT （CBCT） before and after treatment. Grey scale translation error registration was used, and the results of registration were analyzed. The setup errors in x-axis （left-right direction） , y-axis （cranial-caudal direction）, and z-axis （ anterior-posterior direction） were compared between the two groups. Results There was no significant difference in the absolute setup error in the y-axis between the two groups （2.13±0. 64 mm vs.2.61 ± 1.17 mm,P-0. 399）, while group A showed significantly lower absolute setup errors in the x-axis and z-axis than group B （x-axis：1.51±0. 28 mm vs. 2.70±1.05 mm,P=0. 039;with an error rate of 7.41% vs. 42. 59% ;z-axis ： 1.10±0. 29 mm vs. 2.37±0. 71 mm, P= 0. 002 ; with an error rate of 1.85% vs. 35.19% ）. Conclusions In the radiotherapy positioning for rectal cancer, fixation of both lower limbs with negative pressure vacuum cushion effectively avoids the translation and rotation of both lower limbs, reduces absolute setup errors, and has higher accuracy than fixation of both ankles with self-made foam mat.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2016年第9期955-958,共4页
Chinese Journal of Radiation Oncology
关键词
体层摄影术X线计算机
锥形束
千伏级
真空垫固定
泡沫脚垫固定
摆位误差
直肠肿瘤/放射疗法
Tomography, X-ray computed, cone beam, kilovolt
Negative pressure vacuum cushion fixation
Self-made foam mat fixation
Set-up error
Rectal neoplasms/radiotherapy
