锥形束CT引导乳腺癌放射治疗的探讨

目的：探讨锥形束CT（Cone-Beam CT,CBCT）在乳腺癌三维适形或调强放射治疗位置精度保证中的应用。方法：采用Varian-21EX直线加速器机载影像系统（OBI）,在适形或调强放射治疗前行锥形束CT扫描,系统自动重建成断层图像,获得患者三维方向的摆位数据,直接与治疗计划CT扫描图像相匹配后得出两者间的误差数据,对误差予以校正后行精确治疗。结果：经锥形束CT扫描并校正后,左右、腹背和头脚方向的位置误差值分别由（1.7±3.25）mm、（0.9±1.27）mm、（2.1±4.31）mm下降至（0.6±1.38）mm、（0.2±0.72）mm、（0.8±1.65）mm。结论：CBCT对于乳腺癌适形或调强放射治疗的精确实施具有重要作用。

Discussion of Cone-beam CT-guided Radiotherapy for Breast Cancer

Objective To study the cone-beam CT（CBCT）in breast cancer three-dimensional conformal or intensity modu-lated radiation therapy positional accuracy assurance applications.Methods Varian-21EX linear accelerator-board imaging system（OBI）was applied in the conformal or intensity modulated radiation therapy before the line cone-beam CT（CBCT）scanning.The system automatically produced CT reconstruction images to obtain patients＇ three-dimensional pendulum-bit data,which were compared with and directly with the treatment planning CT scan image to determine the error.Then pre-cise treatment was performed after the error was corrected.Results The error values on the left-right,belly-back and head-foot were decreased from（1.7±3.25）mm to（0.6±1.38）mm,from（0.9±1.27）mm to（0.2±0.72）mm,from（2.1±4.31）mm to（0.8±1.65）mm respectively.Conclusion CBCT for breast cancer conformal or intensity modulated radiation therapy has an important role in the precise implementation.