Chiche Dylan, Taillandier Luc, Blonski Marie, Planel Sophie, Obara Tiphaine, Anxionnat René, Rech Fabien
Université de Lorraine, CHRU-Nancy, Service de Neuroradiologie diagnostique et thérapeutique, Nancy, France.
Université de Lorraine, CHRU-Nancy, Service de Neurologie, Nancy, France; Université de Lorraine, Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Automatique de Nancy (CRAN), Nancy, France.
World Neurosurg. 2025 Feb;194:123382. doi: 10.1016/j.wneu.2024.10.111. Epub 2024 Nov 21.
Diffuse low-grade gliomas are rare brain tumors transforming to higher grade even with surgery, chemotherapy, and radiotherapy. Their preferential infiltration of white matter tracts, beyond tumor boundaries on fluid-attenuated inversion recovery (FLAIR), make difficult to plan focal treatment such as surgery or radiotherapy and monitor response to chemotherapy. Diffusion tensor imaging (DTI) might reflect this infiltration of white matter tracts. The aim of our study is to assess how DTI signal in the peritumoral zone might be modified before FLAIR tumor progression appears at 1-year follow-up.
The study retrospectively enrolled 5 patients who met inclusion criteria: DTI with 25 directions, T1 and FLAIR at initial imaging; FLAIR at one-year follow-up. Patients with surgery, radiotherapy, and chemotherapy completed less than 2 years before initial imaging were excluded. FLAIR tumor progression, named progression mask, was assessed by subtracting tumor masks between initial imaging and one-year follow-up. Initial DTI signal was analyzed within this progression mask and compared with the healthy contralateral side.
Tumor progression was confirmed for the 5 patients at 1 year. All patients showed pre-existing DTI signal abnormalities within the progression mask. Mean fractional anisotropy (P = 0.03) was lower in the progression mask, whereas mean diffusivity, axial diffusivity, and radial diffusivity mean (P = 0.03) was higher in the progression mask, compared with the healthy side.
This study shows pre-existing DTI signal abnormalities in regions with tumor progression at 1 year. Such abnormalities could correspond to a tumor infiltration not yet visible on FLAIR. This might be helpful to predict tumor progression and allow to adapt the therapeutic strategy.
弥漫性低级别胶质瘤是一种罕见的脑肿瘤，即使经过手术、化疗和放疗，仍会向高级别转变。它们对白质束的优先浸润超出了液体衰减反转恢复序列（FLAIR）上的肿瘤边界，使得难以规划手术或放疗等局部治疗以及监测化疗反应。扩散张量成像（DTI）可能反映这种白质束浸润情况。我们研究的目的是评估在1年随访时FLAIR序列上肿瘤进展出现之前，瘤周区域的DTI信号如何发生改变。
本研究回顾性纳入了5例符合纳入标准的患者：初始成像时行25个方向的DTI、T1和FLAIR序列检查；1年随访时行FLAIR序列检查。排除初始成像前手术、放疗和化疗完成时间少于2年的患者。通过减去初始成像和1年随访之间的肿瘤掩码来评估FLAIR序列上的肿瘤进展，即进展掩码。在这个进展掩码内分析初始DTI信号，并与对侧健康脑组织进行比较。
5例患者在1年时均证实有肿瘤进展。所有患者在进展掩码内均显示出先前存在的DTI信号异常。与健康侧相比，进展掩码内的平均各向异性分数（P = 0.03）较低，而平均扩散率、轴向扩散率和径向扩散率均值（P = 0.03）较高。
本研究显示在1年时肿瘤进展区域存在先前存在的DTI信号异常。这种异常可能对应于FLAIR序列上尚未可见的肿瘤浸润。这可能有助于预测肿瘤进展并调整治疗策略。
