目的：探讨鼻咽癌 IMRT 中通过听觉器官分区限制剂量方式优化计划对降低听觉器官剂量的影响。方法共选取223例鼻咽癌患者分为 A、B 两组。 A 组114例，通过提高听觉器官 Dmean限制的调强优化权重等级方法设计 IMRT 计划。 B 组109例，以...目的：探讨鼻咽癌 IMRT 中通过听觉器官分区限制剂量方式优化计划对降低听觉器官剂量的影响。方法共选取223例鼻咽癌患者分为 A、B 两组。 A 组114例，通过提高听觉器官 Dmean限制的调强优化权重等级方法设计 IMRT 计划。 B 组109例，以 PTV 外放5 mm 为分割线将听觉器官分成高剂量和低剂量区，限制听觉器官高剂量区剂量不高于靶区处方剂量，听觉器官低剂量区剂量不高于靶区处方剂量一半作为调强优化参数设计放疗计划。成组 t 检验组间差异。结果 T1、T2、T3、T4期中 B 组耳鼓室腔（中耳） Dmean 均值较 A 组分别减少17.7％、22.4％、15.7％、14.2％（P＝0.000、0.000、0.000、0.000）；耳蜗 Dmean均值分别减少11.0％、20.1％、10.0％、9.0％（P＝0.004、0.000、0.007、0.036）；前庭 Dmean均值分别减少22.6％、31.8％、20.6％、21.4％（P＝0.000、0.000、0.000、0.000）。 B组骨性段咽鼓管 Dmean 均值较 A 组无改善（减少3.4％、6.8％、3.6％、0.1％；P＝0.291、0.006、0.155、0.963）。结论听觉器官分区限制剂量方法能有效降低听觉器官剂量，减小听觉器官放射损伤，更好地保护听觉功能。展开更多
The purpose of this study is to develop a mathematical model of the spiral basilar membrane in the center of the cochlea, which plays an important role in the mammalian auditory system. The basilar membrane transmits ...The purpose of this study is to develop a mathematical model of the spiral basilar membrane in the center of the cochlea, which plays an important role in the mammalian auditory system. The basilar membrane transmits sound vibrations, which are converted into electrical potential changes by the inner hair cells. The basilar membrane is thought to lie on a locally undistorted curved surface because the inner hair cells, which are arranged in an orderly fashion on the basilar membrane, respond to their location-specific frequencies. In mammals, the number of rotations of this surface and the rate of change of its width with each rotation are different. It turns out that by modifying the right helicoid, we can obtain a mathematical model that satisfies these points. In conclusion, even though the three-dimensional structure of the basilar membrane varies among species, this model can reproduce this structure. This further suggests that there are common genetic determinants of cochlear development in mammals. From a practical standpoint, this may be useful for creating cochlear implants.展开更多
文摘目的：探讨鼻咽癌 IMRT 中通过听觉器官分区限制剂量方式优化计划对降低听觉器官剂量的影响。方法共选取223例鼻咽癌患者分为 A、B 两组。 A 组114例，通过提高听觉器官 Dmean限制的调强优化权重等级方法设计 IMRT 计划。 B 组109例，以 PTV 外放5 mm 为分割线将听觉器官分成高剂量和低剂量区，限制听觉器官高剂量区剂量不高于靶区处方剂量，听觉器官低剂量区剂量不高于靶区处方剂量一半作为调强优化参数设计放疗计划。成组 t 检验组间差异。结果 T1、T2、T3、T4期中 B 组耳鼓室腔（中耳） Dmean 均值较 A 组分别减少17.7％、22.4％、15.7％、14.2％（P＝0.000、0.000、0.000、0.000）；耳蜗 Dmean均值分别减少11.0％、20.1％、10.0％、9.0％（P＝0.004、0.000、0.007、0.036）；前庭 Dmean均值分别减少22.6％、31.8％、20.6％、21.4％（P＝0.000、0.000、0.000、0.000）。 B组骨性段咽鼓管 Dmean 均值较 A 组无改善（减少3.4％、6.8％、3.6％、0.1％；P＝0.291、0.006、0.155、0.963）。结论听觉器官分区限制剂量方法能有效降低听觉器官剂量，减小听觉器官放射损伤，更好地保护听觉功能。
文摘The purpose of this study is to develop a mathematical model of the spiral basilar membrane in the center of the cochlea, which plays an important role in the mammalian auditory system. The basilar membrane transmits sound vibrations, which are converted into electrical potential changes by the inner hair cells. The basilar membrane is thought to lie on a locally undistorted curved surface because the inner hair cells, which are arranged in an orderly fashion on the basilar membrane, respond to their location-specific frequencies. In mammals, the number of rotations of this surface and the rate of change of its width with each rotation are different. It turns out that by modifying the right helicoid, we can obtain a mathematical model that satisfies these points. In conclusion, even though the three-dimensional structure of the basilar membrane varies among species, this model can reproduce this structure. This further suggests that there are common genetic determinants of cochlear development in mammals. From a practical standpoint, this may be useful for creating cochlear implants.
