目的：分析鼻咽癌调强放疗对双侧内耳受量的影响。方法：选择2015年5月至12月就诊于成都军区总医院50例经病理确诊为鼻咽癌的患者，所有患者均接受30次调强放疗。再由一名主治医师在原始的CT图像上勾画出双侧的耳蜗、前庭及内耳道，并在计划的优化过程中对上述结构进行条件一致的剂量限定，最后通过DVH图对上述结构进行剂量分析，包括最大剂量点（Dmax ）、最小剂量点（Dmin ）及平均剂量（Dmean ）。结果：左侧耳蜗的最大剂量点、最小剂量点及平均剂量的均值分别为5366．3cGy、3981．2cGy、4550．1cGy；左侧前庭分别为4323．2cGy、3310．8cGy、3821．1cGy；左侧内耳道分别为5290．8cGy、3828．7cGy、4453．6cGy；右侧耳蜗的最大剂量点、最小剂量点及平均剂量的均值分别为5344．5cGy、3954．2cGy、4550．1cGy；右侧前庭分别为4368．3cGy、3262．9cGy、3796．0cGy；右侧内耳道分别为5165．0cGy、3765．2cGy、4375．2cGy。结论：在鼻咽癌的调强放疗计划设计过程中对内耳结构进行剂量限定，能在不减少靶区受量的同时有效的降低内耳结构的受照射剂量。%Objective:To analyze the dose of bilateral inner ear in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT).Methods:A total of 50 NPC cases from May to December 2015 received the IMRT with 30 fractions for pathological diagnosis.An attending physician contoured the bilateral cochlea、vestibule and internal auditory canal in the original CT images.The same weightings were given to these structures during optimization in treatment planning.Finally,we analyzed the dose volume histogram(DVH)of these structures,including the maximum dose (Dmax ),minimum dose (Dmin )and the average dose (Dmean ).Results:The maximum dose of the left cochlea (Dmax ),minimum dose (Dmin )and the average dose (Dmean )were presented re-spectively 5 366.3cGy,3 981.2cGy,4 550.1cGy.The left vestibule were 4 323.2cGy,3 310.8cGy,3 821.1cGy,re-spectively.The left internal auditory canal were 5 290.8cGy,3 828.7cGy,4 453.6cGy,respectively.And the maxi-mum dose of the right cochlea (Dmax),minimum dose (Dmin)and the average dose (Dmean )were presented respec-tively 5 344.5cGy,3 954.2cGy,4 550.1cGy.The right vestibule were 4 368.3cGy,3 262.9cGy,3 796.0cGy,respec-tively.The right internal auditory canal were 5 165.0cGy,3 765.2cGy,4 375.2cGy,respectively.Conclusion:It can not only guarantee the dose of target area but also effectively reduce the dose of inner ear during the optimization of NPC treated with IMRT.
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