应用EPID分析头颈部肿瘤调强放疗的摆位误差  

Analyzing setup error with electron portal images device for head and neck tumors treated with intensity modulated radiation therapy

作　　者：张彦新[1] 戴建荣[1] 易俊林[1] 高黎[1] 章众[1] 魏国友[1] 张连胜[1] 

机构地区：[1]中国医学科学院中国协和医科大学肿瘤医院肿瘤研究所放疗科,北京100021

出　　处：《中华放射肿瘤学杂志》2008年第1期39-42,共4页Chinese Journal of Radiation Oncology

摘　　要：目的通过对头颈部肿瘤患者群体的射野图像回顾性分析，了解患者群体的摆位误差分布情况，为治疗计划设计设置计划靶体积（PTV）时提供依据。方法通过配准数字重建图像（DRR）和电子射野影像装置（EPID）拍摄的正、侧位验证像的骨性解剖结构，计算平移和旋转误差。结果平移误差左右方向为（1．40±1．27）mm，头脚方向为（1．34±1．37）mm，腹背方向为（1．34±1．30）mm；旋转误差冠状面为（0．791±0．976）°，矢状面为（0．531±0．750）°。结论对于头颈部肿瘤调强放疗（IMRT），临床靶体积（CTV）到PTV的外放边界在左右方向宜为3．7mm，头脚及腹背方向宜为3．6mm。考虑到旋转误差，当靶区比较长时靶区两端外放要更大一些。Objective To investigate the setup accuracy of the patients with head and neck cancer, and to provide reference data on the margin between the clinical target volume （CTV） and planning target volume（PTN）. Methods Electron portal images device （EPID） and digitally reconstructed radiographs （DRR） of patients with head and neck tumors were retrospectively analyzed. The translational and rotational deviations were analyzed by registering and comparing the bony structures of EPID and DRR. Results The translational deviations were （ 1.40 ± 1.27） mm, （ 1.34 ± 1.37） mm and （ 1.34 ± 1.30） mm in medi-lateral, cranio-caudal and anterior-posterior directions, respectively. The rotational deviations were （0.791 ± 0. 976）° and （0. 531 ± 0. 750）° in sagittal plane and coronal plane, respectively. Conclusions For the patients with head and neck tumors undergoing intensity modulated radiation therapy, the margins between the CTV and PTV shoukl be 3.7 mm in lateral direction, and 3.6 mm in both cranio-caudal and anteriorposterior directions. Considering the rotational variations, the margin should be expanded at the end of the target.

关 键 词：摆位误差 电子射野影像装置 数字重建图像 调强放射疗法 

分 类 号：R686[医药卫生—骨科学]