Hu Alice, Guida Lelio, Fillon Ludovic, Nabbout Rima, Doz François, Aboubakr Oumaima, Blauwblomme Thomas, Boddaert Nathalie, Dangouloff-Ros Volodia
Pediatric Radiology Department, AP-HP, Hôpital Universitaire Necker-Enfants Malades, F-75015 Paris, France; Université Paris Cité, INSERM U1299, F-75015 Paris, France; Université Paris Cité, UMR 1163, Institut Imagine, F-75015 Paris, France.
Université Paris Cité, UMR 1163, Institut Imagine, F-75015 Paris, France; Pediatric Neurosurgery Department, AP-HP, Hôpital Universitaire Necker-Enfants Malades, F-75015 Paris, France.
J Neuroradiol. 2025 Aug 13;52(6):101377. doi: 10.1016/j.neurad.2025.101377.
Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a minimally invasive alternative for drug-resistant epilepsy and pediatric brain tumors, particularly in deep-seated lesions where open surgery presents significant risks. However, the multimodal imaging characteristics of lesions during and after MRgLITT remain underexplored. This study aims to describe the MRI features of MRgLITT-treated lesions in pediatric patients both intraoperatively and during long-term follow-up.
We conducted a retrospective analysis of 26 pediatric patients(32 procedures) treated using MRgLITT, including focal cortical dysplasias, low-grade tumors and hamartomas. Imaging acquisition included preoperative, intraoperative, and postoperative MRI with advanced sequences(T1-weighted, FLAIR, DWI, ASL perfusion, and MR spectroscopy). Lesion evolution was assessed over a one-year follow-up period.
Intraoperatively, lesions showed a rim of high signal on DWI and on post-contrast T1-weighted images, a lactate peak on MR spectroscopy, and the majority of them had peripheral high signal on FLAIR associated with a low signal core and increased CBF on ASL. During follow-up, lesions may increase in size in the first days or weeks, then decrease in size mainly in the first 3 months and tend to stabilize at 9 months, with persistent gliotic changes on FLAIR sequences. Contrast enhancement resolved in epilepsy-related lesions, but small areas remained in most tumors without correlation with progression.
MRgLITT results in a predictable pattern of imaging changes, with lesion contraction occurring primarily within the first 3 months. Understanding these radiological markers is essential for optimizing post-procedure management and treatment decisions in pediatric epilepsies and tumors.
磁共振引导激光间质热疗（MRgLITT）已成为耐药性癫痫和小儿脑肿瘤的一种微创替代治疗方法，尤其适用于开放性手术风险较大的深部病变。然而，MRgLITT治疗期间及之后病变的多模态成像特征仍未得到充分研究。本研究旨在描述小儿患者经MRgLITT治疗的病变在术中及长期随访期间的MRI特征。
我们对26例接受MRgLITT治疗的小儿患者（32次手术）进行了回顾性分析，这些患者包括局灶性皮质发育异常、低级别肿瘤和错构瘤。成像采集包括术前、术中和术后的MRI，采用先进序列（T1加权、液体衰减反转恢复序列、扩散加权成像、动脉自旋标记灌注成像和磁共振波谱）。在一年的随访期内评估病变的演变情况。
术中，病变在扩散加权成像和增强后T1加权图像上显示高信号边缘，磁共振波谱上有乳酸峰，并且大多数病变在液体衰减反转恢复序列上有外周高信号，伴有低信号核心，动脉自旋标记灌注成像显示脑血流量增加。在随访期间，病变可能在最初几天或几周内增大，然后主要在最初3个月内缩小，并在9个月时趋于稳定，液体衰减反转恢复序列上有持续的胶质增生改变。癫痫相关病变的强化消失，但大多数肿瘤中仍有小面积强化，与进展无关。
MRgLITT导致可预测的成像变化模式，病变缩小主要发生在最初3个月内。了解这些影像学标志物对于优化小儿癫痫和肿瘤的术后管理及治疗决策至关重要。
