Abstract: 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.

Key words: Head and neck cancer, Adaptive radiation therapy, Image-guided radiation therapy, Intensitymodulated radiotherapy, Replanning