鼻咽癌调强放疗中限制剂量与提高保护权重对听觉器官剂量分布影响的研究  

Effects of dose limitation and increased protective weight on dose distribution in auditory organs during intensity-modulated radiotherapy for nasopharyngeal carcinoma

作　　者：倪晓晨[1] 王胜资[1] 李骥[1] 王伟芳[1] 杨钢[1] 

机构地区：[1]复旦大学附属眼耳鼻喉科医院放疗科,上海200031

出　　处：《中华放射肿瘤学杂志》2013年第6期478-481,共4页Chinese Journal of Radiation Oncology

基　　金：上海市浦东新区社会发展局卫生科技项目（PW2009d-7）;上海科学技术委员会医学引导类项目（09411962000）

摘　　要：目的 探讨鼻咽癌调强放疗（IMRT）计划优化过程中降低听觉系统（中耳鼓室腔、骨性段咽鼓管、前庭及耳蜗）平均剂量对放疗中听觉器官功能可能的保护作用.方法 共选取鼻咽癌患者40例（Ⅰ＋Ⅱ期20例,Ⅲ＋Ⅳ期20例）,使用ADAC Pinnacle3 8.0m计划系统的直接子野优化方法进行IMRT计划优化设计.在不影响靶区剂量前提下分别采用限制听觉系统平均剂量方法和提高听觉系统所受保护器官保护权重的优化方法,将听觉系统平均受量与不限制听觉系统各器官平均受量进行分析和评估.结果 在不降低靶区剂量情况下,限制听觉系统平均剂量的听觉系统平均剂量大幅降低（3855.5～5391.3 Gy∶ 2960.3 ～4559.6 Gy,所有P=0.000））,提高优化权重后听觉系统平均剂量进一步降低（3855.5～5391.3 Gy∶2725.4～4271.4 Gy,所有P=0.000））.3种方案Ⅲ＋Ⅳ期的平均剂量均高于Ⅰ＋Ⅱ期的（所有P=0.000）.结论 鼻咽癌IMRT计划设计中听觉系统器官剂量限制可大幅降低听觉系统剂量,而提高保护权重次序也可进一步降低听觉系统剂量；但对听觉系统的保护随患者分期增大可能性减小.Abstract： Objective To investigate the protective effects of reducing average radiation dose and increasing protective weight on the auditory system （tympanic cavity,the bony portion of eustachian tube,vestibule,and cochlea） during intensity-modulated radiotherapy （IMRT） for nasopharyngeal carcinoma （NPC）.Methods The planning system （ADAC Pinnacle3 8.0m） with direct machine parameter optimization was used to optimize the IMRT planning for 40 patients with NPC （stage Ⅰ ＋ Ⅱ：20 patients ;stage Ⅲ ＋ Ⅳ：20 patients）.Without reducing the radiation dose for target volume,the IMRT planning was optimized by limiting the average dose administered to the auditory system or increasing the protective weight for the protected organs in auditory system.The protective effects were assessed by analyzing the average dose received by the auditory system.Results After limiting the average dose administered to the auditory system without reducing the radiation dose for target volume,the average dose received by the auditory system was significantly reduced （3855.5-5391.3 Gy vs 2960.3-4559.6 Gy,P =0.000 for all） ; when the protective weight for the auditory system was increased,the average dose received by the auditory system was even more reduced （3855.5-5391.3 Gy vs 2725.4-4271.4 Gy,P =0.000 for all）.For all three regimens,the average dose was significantly higher in stage Ⅲ ＋ Ⅳ patients than in stage Ⅰ ＋ Ⅱ patients （P =0.000 for all）.Conclusions For the IMRT planning for NPC,limiting the average dose administered to the auditory system can greatly reduce the average dose received by the auditory system,and increasing the protective weight for the auditory system can further reduce the average dose received by the auditory system.However,the protective effect on the auditory system may be reduced as the stage of NPC increases.

关 键 词：听觉器官 剂量限制 优化权重 鼻咽肿瘤 调强放射疗法 

分 类 号：R739.63[医药卫生—肿瘤]