Holikova Klara, Selingerova Iveta, Pospisil Petr, Bulik Martin, Hynkova Ludmila, Kolouskova Ivana, Hnidakova Lucie, Burkon Petr, Slavik Marek, Sana Jiri, Holecek Tomas, Vanicek Jiri, Slampa Pavel, Jancalek Radim, Kazda Tomas
Department of Medical Imaging, St. Anne's University Hospital Brno and Faculty of Medicine, Masaryk University, Brno, Czech Republic.
Research Center for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czech Republic.
Neurooncol Adv. 2024 Mar 20;6(1):vdae040. doi: 10.1093/noajnl/vdae040. eCollection 2024 Jan-Dec.
Changes in the hippocampus after brain metastases radiotherapy can significantly impact neurocognitive functions. Numerous studies document hippocampal atrophy correlating with the radiation dose. This study aims to elucidate volumetric changes in patients undergoing whole-brain radiotherapy (WBRT) or targeted stereotactic radiotherapy (SRT) and to explore volumetric changes in the individual subregions of the hippocampus.
Ten patients indicated to WBRT and 18 to SRT underwent brain magnetic resonance before radiotherapy and after 4 months. A structural T1-weighted sequence was used for volumetric analysis, and the software FreeSurfer was employed as the tool for the volumetry evaluation of 19 individual hippocampal subregions.
The volume of the whole hippocampus, segmented by the software, was larger than the volume outlined by the radiation oncologist. No significant differences in volume changes were observed in the right hippocampus. In the left hippocampus, the only subregion with a smaller volume after WBRT was the granular cells and molecular layers of the dentate gyrus (GC-ML-DG) region (median change -5 mm, median volume 137 vs. 135 mm; = .027), the region of the presumed location of neuronal progenitors.
Our study enriches the theory that the loss of neural stem cells is involved in cognitive decline after radiotherapy, contributes to the understanding of cognitive impairment, and advocates for the need for SRT whenever possible to preserve cognitive functions in patients undergoing brain radiotherapy.
脑转移瘤放疗后海马体的变化会显著影响神经认知功能。大量研究表明海马体萎缩与放射剂量相关。本研究旨在阐明接受全脑放疗（WBRT）或立体定向放射治疗（SRT）的患者的体积变化，并探讨海马体各个亚区域的体积变化。
10例接受WBRT的患者和18例接受SRT的患者在放疗前及放疗后4个月接受脑部磁共振成像检查。采用结构性T1加权序列进行体积分析，并使用FreeSurfer软件作为评估19个海马体亚区域体积的工具。
软件分割得到的整个海马体体积大于放射肿瘤学家勾勒出的体积。右侧海马体体积变化无显著差异。在左侧海马体中，WBRT后体积较小的唯一亚区域是齿状回颗粒细胞和分子层（GC-ML-DG）区域（中位数变化-5mm，中位数体积137对135mm；P = 0.027），该区域被认为是神经元祖细胞的假定位置。
我们的研究丰富了神经干细胞丢失与放疗后认知功能下降有关的理论，有助于理解认知障碍，并主张在可能的情况下尽可能采用SRT以保留接受脑部放疗患者的认知功能。
