精确放射治疗中的影像引导技术成像原理和应用

Imaging principle and application of image-guided technology in the precise radiotherapy

立体定向消融治疗是代表性的精确放疗技术,具有精准定位、精准照射、高效微创等特点,已在脑转移瘤、早期非小细胞肺癌治疗中取得与手术相当的效果。其中影像引导技术在精确放疗过程管理中发挥关键作用,分为单一成像系统和组合成像系统。前者有超声引导、电子射野成像引导、锥形束和扇形束CT引导、核磁引导以及电磁追踪等技术,后者有ExacTrac X射线六维立体定向引导系统等。本文将回顾当前应用的影像引导技术,分析成像原理以及如何改善治疗准确性和缩小肿瘤周围正常组织受照射体积,探索未来融合发展前景。

Stereotactic ablative radiation therapy is one of representative precise radiotherapy technology and has characteristics of precise simulation, accurate delivery, good performance and minimal adverse effect, which has acquired similar results with surgery in the treatment of brain metastasis and early stage non-small cell lung cancer. During the precise delivery management, the image-guided technologies play an important role, which include single imaging system and the combination of imaging system. The former are guided by ultrasound, electron beam, cone beam computer tomography（CT）, fan beam CT, nuclear magnetic image and electromagnetic tracking technology; the latter are guided by Exac Trac X-ray six dimensional directional guidance system, etc. This article will review current application of image-guided technology and analyze imaging principle and how to improve the accuracy and shrink surrounding normal tissues irradiated volume, explore the future development.