鼻咽癌患者放疗期间的灰质体积变化:基于体素的形态学分析

Voxel-based morphological study on the changes of brain structure during radiotherapy of nasopharyngeal carcinoma

目的研究鼻咽癌(nasopharyngeal carcinoma,NPC)患者的大脑灰质体积在放疗期间的变化及其与放疗剂量的关系。材料与方法选取21例首发NPC患者,分别在放疗前(放疗开始前1~2 d)、放疗中(放疗开始后19~20 d)和放疗后(放疗结束后1~2 d)进行颅脑3D-T1加权MRI扫描,使用基于体素的形态测量学方法分析脑灰质体积在放疗期间的改变,并进行体积改变和剂量大小的相关性分析。结果与放疗前相比,NPC患者在放疗中颞叶(双侧梭状回、右侧颞上回、右侧颞中回、右侧颞下回)、枕叶(左侧舌回、右侧矩状回)、额叶(左侧眶部额中回、左侧眶部额下回)、边缘叶(左侧岛叶、双侧前扣带回)、左侧小脑灰质体积减小(cluster水平FWE校正,P<0.001);NPC患者在放疗后,上述颞叶、枕叶、额叶、边缘叶和小脑灰质体积仍显著减小,同时出现右侧岛叶,左侧颞叶、双侧额上回、右侧眶部额下回、右侧小脑、右侧海马旁回灰质体积减小(cluster水平FWE校正,P<0.001)。左侧小脑灰质体积变化与放疗剂量呈正相关(r=0.503,P=0.020)。结论NPC患者在放疗期间的大脑灰质结构已发生了形态学改变。

Objective:To study the changes in cerebral gray matter volume in patients with nasopharyngeal carcinoma(NPC)during radiotherapy and its relationship with radiotherapy dose.Materials and Methods:Twenty-one patients with first-episode NPC were selected for MRI scanning before radiotherapy(1-2 days before radiotherapy),during radiotherapy(19-20 days after radiotherapy),and after radiotherapy(1-2 days after radiotherapy).Voxel-based morphometry(VBM)was used to analyze the changes in cerebral gray matter volume during radiotherapy;the correlation between volume change and the dose was analyzed.Results:Compared with those before radiotherapy,the volume of the temporal lobe(bilateral fusiform gyrus,right superior temporal gyrus,right middle temporal gyrus,right inferior temporal gyrus),occipital lobe(left lingual gyrus,right rectangular gyrus),frontal lobe(left orbital middle frontal gyrus,left orbital inferior frontal gyrus),marginal lobe(left insular lobe,bilateral anterior cingulate gyrus),and left cerebellar gray matter decreased during radiotherapy in NPC patients(cluster level FWE correction,P<0.001);After radiotherapy,the volume of gray matter in the temporal lobe,occipital lobe,frontal lobe,marginal lobe and cerebellum of NPC patients still decreased significantly,and the volume of gray matter in the right insular lobe,left temporal lobe,bilateral superior frontal gyrus,right orbital inferior frontal gyrus,right cerebellum,and right parahippocampal gyrus also decreased(cluster level FWE correction,P<0.001).The volume change of left cerebellar gray matter was positively correlated with the radiation dose(r=0.503,P=0.020).Conclusions:The brain gray matter structure of NPC patients has undergone morphological changes during radiotherapy.