高级弥散 MRI 为胶质母细胞瘤与脑转移瘤相比，存在轴突微观结构改变和逐渐发生的肿瘤周围浸润提供了证据。

Advanced diffusion MRI provides evidence for altered axonal microstructure and gradual peritumoral infiltration in GBM in comparison to brain metastases.

机构信息

Department of Neuroradiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106, Freiburg, Germany.

Dept. of Neuroradiology, University Medical Center Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany.

出版信息

Clin Neuroradiol. 2024 Sep;34(3):703-711. doi: 10.1007/s00062-024-01416-0. Epub 2024 Apr 29.

DOI:10.1007/s00062-024-01416-0

PMID:38683350

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11339137/

Abstract

PURPOSE

In contrast to peritumoral edema in metastases, GBM is histopathologically characterized by infiltrating tumor cells within the T2 signal alterations. We hypothesized that depending on the distance from the outline of the contrast-enhancing tumor we might reveal imaging evidence of gradual peritumoral infiltration in GBM and predominantly vasogenic edema around metastases. We thus investigated the gradual change of advanced diffusion metrics with the peritumoral zone in metastases and GBM.

METHODS

In 30 patients with GBM and 28 with brain metastases, peritumoral T2 hyperintensity was segmented in 33% partitions based on the total volume beginning at the enhancing tumor margin and divided into inner, middle and outer zones. Diffusion Tensor Imaging (DTI)-derived fractional anisotropy and mean diffusivity as well as Diffusion Microstructure Imaging (DMI)-based parameters Dax-intra, Dax-extra, V‑CSF and V-intra were employed to assess group-wise differences between inner and outer zones as well as within-group gradients between the inner and outer zones.

RESULTS

In metastases, fractional anisotropy and Dax-extra were significantly reduced in the inner zone compared to the outer zone (FA p = 0.01; Dax-extra p = 0.03). In GBM, we noted a reduced Dax-extra and significantly lower intraaxonal volume fraction (Dax-extra p = 0.008, V‑intra p = 0.006) accompanied by elevated axial intraaxonal diffusivity in the inner zone (p = 0.035). Between-group comparison of the outer to the inner zones revealed significantly higher gradients in metastases over GBM for FA (p = 0.04) as well as the axial diffusivity in the intra- (p = 0.02) and extraaxonal compartment (p < 0.001).

CONCLUSION

Our findings provide evidence of gradual alterations within the peritumoral zone of brain tumors. These are compatible with predominant (vasogenic) edema formation in metastases, whereas our findings in GBM are in line with an axonal destructive component in the immediate peritumoral area and evidence of tumor cell infiltration with accentuation in the tumor's vicinity.

摘要

目的

与转移瘤的瘤周水肿相反，GBM 在组织病理学上的特征是在 T2 信号改变中浸润肿瘤细胞。我们假设，根据与增强肿瘤轮廓的距离，我们可能会在 GBM 中发现逐渐出现的瘤周浸润的影像学证据，而在转移瘤周围主要是血管源性水肿。因此，我们研究了转移瘤和 GBM 中高级扩散指标与瘤周区的逐渐变化。

方法

在 30 例 GBM 患者和 28 例脑转移瘤患者中，根据从增强肿瘤边缘开始的总容积，将瘤周 T2 高信号按 33%的分区进行分割，并分为内、中、外区。采用弥散张量成像（DTI）衍生的各向异性分数和平均弥散度以及弥散微观结构成像（DMI）衍生的参数 Dax-intra、Dax-extra、V-CSF 和 V-intra，评估内、外区之间的组间差异以及内、外区之间的组内梯度。

结果

在转移瘤中，与外区相比，内区的各向异性分数和 Dax-extra 显著降低（FA p=0.01；Dax-extra p=0.03）。在 GBM 中，我们观察到 Dax-extra 降低和明显较低的轴内容积分数（Dax-extra p=0.008，V-intra p=0.006），同时内区的轴内轴向弥散度升高（p=0.035）。与外区相比，内区的组间比较显示，FA （p=0.04）以及轴内（p=0.02）和轴外（p<0.001）的轴向弥散度在转移瘤中的梯度明显高于 GBM。