ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.
ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France; Radiation Oncology Department, Institut Claudius Regaud- Institut Universitaire du Cancer de Toulouse-Oncopole, Toulouse, France.
Clin Oncol (R Coll Radiol). 2024 Jan;36(1):56-64. doi: 10.1016/j.clon.2023.09.015. Epub 2023 Sep 29.
Posterior fossa tumours (PFTs), which account for two-thirds of paediatric brain tumours, are successfully treated in about 70% of patients, but most survivors experience long-term cognitive impairment. We evaluated arterial spin labelling (ASL), a common, non-invasive magnetic resonance imaging (MRI) technique, as a biomarker of cognitive impairment in a paediatric PFT survivor population.
Sixty participants were prospectively analysed. PFT survivors were at least 5 years post-treatment and had been treated as appropriate for their age and type of tumour. Group 1 had received radiotherapy and Group 2 had not. Group 3 were healthy controls matched to Group 1 for age, sex and handedness. All participants underwent cognitive assessment and multimodal MRI, including an ASL perfusion sequence. We used semi-quantitative ASL methods to assess differences in mean perfusion in the thalamus, caudate, putamen and hippocampus.
Statistically, no significant associations between cognitive data and radiation doses were identified. Compared with healthy controls, Group 1 patients had significantly lower overall mean perfusion values (20-30% lower, depending on the cerebral structure) and Group 2 had slightly lower mean perfusion values (5-10% lower). Perfusion values did not correlate with total prescribed irradiation doses nor with doses received by different cerebral structures. Episodic and semantic memory test scores were significantly lower in Group 1 and correlated with lower mean absolute perfusion values in the hippocampus (P < 0.04).
These preliminary results indicate that radiotherapy affects the perfusion of specific cerebral structures and identify perfusion as a potential biomarker of hippocampus-dependent memory deficit.
后颅窝肿瘤（PFT）占儿童脑肿瘤的三分之二，约 70%的患者治疗成功，但大多数幸存者都存在长期认知障碍。我们评估了动脉自旋标记（ASL），这是一种常见的、非侵入性的磁共振成像（MRI）技术，作为儿童 PFT 幸存者人群认知障碍的生物标志物。
对 60 名参与者进行了前瞻性分析。PFT 幸存者的治疗时间至少为 5 年，且已根据其年龄和肿瘤类型进行了适当治疗。第 1 组接受了放疗，第 2 组未接受放疗。第 3 组为与第 1 组年龄、性别和惯用手相匹配的健康对照组。所有参与者均接受认知评估和多模态 MRI，包括 ASL 灌注序列。我们使用半定量 ASL 方法评估丘脑、尾状核、壳核和海马的平均灌注差异。
统计分析未发现认知数据与辐射剂量之间存在显著相关性。与健康对照组相比，第 1 组患者的总体平均灌注值明显降低（取决于大脑结构，降低 20-30%），第 2 组患者的平均灌注值略低（降低 5-10%）。灌注值与总规定照射剂量或不同脑结构接受的剂量均无相关性。第 1 组的情景记忆和语义记忆测试得分明显较低，且与海马体的平均绝对灌注值较低显著相关（P < 0.04）。
这些初步结果表明放疗会影响特定大脑结构的灌注，并确定灌注值是海马体依赖性记忆缺陷的潜在生物标志物。
