Objective: To compare the differences of radiation-induced doses between 18F-FDG-PET/CT and CT/MRI-guided target delineation in nasopharyngeal carcinoma in intensity-modulated radiotherapy. Methods: A total of 31 patients with locally advanced nasopharyngeal carcinoma receiving treatment in our hospital from December 2016 to December 2017 were studied in this research, and 18F-FDG-PET/CT and CT/MRI were used to guide the target delineation to develop an intensity-modulated radiotherapy plan(experimental group and control group). The dose differences between GTV and endangered organs in the two groups were compared. Results: Comparison of primary tumor volume: PET/CT was smaller than CT/MRI, and volumes of T3 and T4 were significantly different (P
