头颈部肿瘤自适应放疗的研究进展

调强放射治疗(intensity-modulated radiation therapy，IMRT)是头颈部恶性肿瘤的重要治疗方法之一。但在IMRT过程中，摆位误差、解剖结构的移位及变形、肿瘤退缩或进展及形状改变等，可导致靶区和危及器官的照射剂量和体积出现“偏差”，影响IMRT的精确性。图像引导的放射治疗(image-guidedradiotherapy，IGRT)可部分纠正摆位误差，从而提高放疗精度，但不能解决非刚性误差以及解剖结构变化带来的剂量差异。自适应放射治疗(adaptive radiation therapy，ART)是在IMRT和IGRT基础上出现的新型放疗技术，能修正IMRT和IGRT靶区和危及器官的偏差。通过患者图像、剂量等反馈信息对原治疗计划重新优化和调整，这是一种基于反馈控制理论的治疗策略。其目的是使放射治疗更加精确化、个体化。

Progress in research of adaptive radiation therapy for head and neck cancer

Intensity-modulated radiation therapy (IMRT) is one of the most important techniques for the treatment of head and neck cancers. During IMRT, the accuracy of radiation dose delivery is limited by errors in patient treatment positioning, inter-treatment, and intra-treatment variation of organ position, size, and shape. Image-guided radiation therapy (IGRT) may partly correct these errors and further improve the radiation dose delivery. However, the dose deviation caused by internal organ motion or non-rigid motion cannot be simply solved by IGRT technique. Nowadays, adaptive radiation therapy (ART) has been introduced to minimize the negative effects of treatment position uncertainty which normally exist in either IMRT or IGRT, and to compensate the target coverage and clinical outcome. Based on the patient’s pre-treatment images and relative information such as dose deviation, ART may provide a better strategy for online treatment. Under the help of ART technique, radiotherapy can be more accurate and more personalized.