CBCT在放射治疗摆位中的临床应用  

CBCT Clinical Application in Setup Error

作　　者：陈丽[1] 武文娟[1] 花威[1] 袁一枫[1] 陈婷婷[1] 

机构地区：[1]江苏省苏北人民医院肿瘤科,225001

出　　处：《实用癌症杂志》2012年第4期394-396,共3页The Practical Journal of Cancer

摘　　要：目的探讨锥形束CT(CBCT)对不同部位肿瘤分次治疗间的摆位误差,为CTV外放PTV提供依据。方法分别对头颈部肿瘤患者(头颈肩型热塑模固定)和胸部肿瘤患者(体部热塑模固定)的135次、211次CBCT结果进行分析,根据Stroom公式:PTV外放=2∑+0.7σ,计算Margin的前后、头脚、左右方向的范围。结果头颈部肿瘤患者前后方向的最大偏差值高达7 mm,且向源皮距偏大方向移动占97.15%。3个方向大于3 mm偏差的均在10%以下。胸部肿瘤患者的头脚方向摆位误差最大,大于5 mm的达21.74%。头颈部肿瘤CTV～PTV即Margin的前后、头脚、左右方向分别为4.94 mm、4.19 mm、4.43 mm,胸部肿瘤Margin的前后、头脚、左右方向分别为4.28 mm、8.81 mm、5.15 mm。结论 CBCT可以提高摆位的精度,减少摆位的不确定性,为正确设定计划靶体积(PTV)提供了依据。Objective To analyze interfractional setup errors for different tumor sites by cone beam CT（CBCT）scanning and to provide the basis for calculating the external margins from clinical target volume（CTV）to planning target volume（PTV）.Methods The setup errors were gathered from 135 sets of CBCT in head and neck patients,211 sets of CBCT in chest tumor patients.Calculation of CTV-PTV margings was based on the recipes of Stroom et al：2∑＋0.7σ.Results In patients with head and neck cancer,the maximum movement of anterior-posterior was 7mm,and in 97.15% of cases,the movement was toward a larger source skin distance.In all three directions,the movement larger than 3mm was seen in less than 10%,and larger than 5mm was seen in less than 21.74%.The margins of the anterior-posterior,cranial-caudal,and interior-exterior direction were 4.94mm,4.19mm,and 4.43mm in patients with head and neck cancer,whereas the margins were 4.28 mm,8.81 mm,and 5.15 mm in patients with thoractic tumors.Conclusion CBCT can improve the positioning precision,and provide a basis for delineation of PTV

关 键 词：摆位误差 锥形束CT 放射治疗 

分 类 号：R730.55[医药卫生—肿瘤]