Center for the Study of Applied Psychology & MRI Center, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou, 510631, People's Republic of China.
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Guangzhou, 510060, People's Republic of China.
Brain Imaging Behav. 2020 Dec;14(6):2745-2761. doi: 10.1007/s11682-019-00224-2.
Previous neuroimaging studies revealed radiation-induced brain injury in patients with nasopharyngeal carcinoma (NPC) in the years after radiotherapy (RT). These injuries may be associated with structural and functional alterations. However, differences in the brain structural connectivity of NPC patients at different times after RT, especially in the early-delayed period, remain unclear. We acquired diffusion tensor imaging (DTI) data from three groups of NPC patients, 25 in the pre-RT (before RT) group, 22 in the early-delayed (1-6 months) period (post-RT-ED) group, and 33 in the late-delayed (>6 months) period (post-RT-LD) group. Then, we constructed brain white matter (WM) structural networks and used graph theory to compare their between-group differences. The NPC patients in the post-RT-ED group showed decreased global properties when compared with the pre-RT group. We also detected the nodes with between-group differences in nodal parameters. The nodes that differed between the post-RT-ED and pre-RT groups were mainly located in the default mode (DMN) and central executive networks (CEN); those that differed between the post-RT-LD and pre-RT groups were located in the limbic system; and those that differed between the post-RT-LD and post-RT-ED groups were mainly in the DMN. These findings may indicate that radiation-induced brain injury begins in the early-delayed period and that a reorganization strategy begins in the late-delayed period. Our findings may provide new insight into the pathogenesis of radiation-induced brain injury in normal-appearing brain tissue from the network perspective.
先前的神经影像学研究揭示了鼻咽癌（NPC）患者在放射治疗（RT）后的数年中存在放射性脑损伤。这些损伤可能与结构和功能改变有关。然而，RT 后不同时间 NPC 患者脑结构连接的差异，尤其是在早期延迟期，尚不清楚。我们从三组 NPC 患者中获得了弥散张量成像（DTI）数据，分别为 25 名预 RT（RT 前）组、22 名早期延迟（1-6 个月）期（RT-ED 后）组和 33 名晚期延迟（>6 个月）期（RT-LD 后）组。然后，我们构建了脑白质（WM）结构网络，并使用图论比较了它们之间的组间差异。与预 RT 组相比，RT-ED 后组的全局属性降低。我们还检测了节点间参数的组间差异。RT-ED 后组与预 RT 组之间存在差异的节点主要位于默认模式（DMN）和中央执行网络（CEN）中；RT-LD 后组与预 RT 组之间存在差异的节点主要位于边缘系统中；RT-LD 后组与 RT-ED 后组之间存在差异的节点主要位于 DMN 中。这些发现可能表明放射性脑损伤始于早期延迟期，而在晚期延迟期开始了一种重组策略。我们的研究结果可能从网络角度为正常脑组织结构中的放射性脑损伤的发病机制提供新的见解。
