Radiation Oncology Department, Oncopole Claudius Regaud- Institut Universitaire du Cancer de Toulouse-Oncopole, Toulouse, France; ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.
ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.
Clin Oncol (R Coll Radiol). 2024 Nov;36(11):e439-e447. doi: 10.1016/j.clon.2024.07.008. Epub 2024 Jul 22.
The cerebellum is a key structure in working and procedural memory. The aim of the present prospective exploratory study was to investigate, the metabolic characteristics of the cerebellum in posterior fossa tumor (PFT) survivors using 3D proton magnetic resonance spectroscopy imaging (3D MRSI), to determine whether metabolites could be useful biomarkers of memory impairment.
Sixty participants were included in the IMPALA study, divided into three groups: 22 irradiated PFT, 17 nonirradiated PFT, and 21 healthy controls matched with irradiated PFT for age, sex, and handedness. PFT survivors were treated at least 5 years ago, either by surgery or a combination of surgery, chemotherapy, and radiotherapy. All participants underwent working and procedural memory tests and multimodal MRI including a 3D MRSI sequence. N-acetylaspartate (NAA), choline (Cho), creatine (Cr), and lactate (Lac) metabolite values were extracted from the cerebellum for comparisons between groups, correlations with neurocognitive test scores, and radiotherapy doses.
Median (range) age at neurocognitive tests was 18 (7-26) years. Median Cho, Cr, NAA, and Lac values, and the ratio of NAA to the sum of metabolites were significantly lower for PFT survivors than for healthy controls (p < 0.05). Scores on working and procedural memory tests were significantly lower for PFT survivors (p < 0.004) and correlated with median and maximum Cho and NAA values (0.28 <r < 0.49, p < 0.04). Except for creatine, the other metabolites were not significantly different between irradiated and nonirradiated survivors. MRSI values in the cerebellum were not correlated with either total dose or doses received by this structure.
Results revealed changes in cerebellar metabolic values in PFT survivors that were closely correlated with memory deficits, suggesting that some metabolites could be used as markers of cognitive decline, but this will require validation on a larger sample size.
小脑是工作记忆和程序性记忆的关键结构。本前瞻性探索性研究的目的是使用 3D 质子磁共振波谱成像（3D MRSI）来研究后颅窝肿瘤（PFT）幸存者小脑的代谢特征，以确定代谢物是否可以作为记忆障碍的有用生物标志物。
IMPALA 研究共纳入 60 名参与者，分为三组：22 名接受放疗的 PFT 幸存者、17 名未接受放疗的 PFT 幸存者和 21 名与接受放疗的 PFT 相匹配的健康对照者，这些对照者在年龄、性别和利手方面相匹配。PFT 幸存者至少在 5 年前接受过治疗，治疗方法是手术或手术联合化疗和放疗。所有参与者均接受了工作记忆和程序性记忆测试以及多模态 MRI 检查，包括 3D MRSI 序列。从小脑提取 N-乙酰天冬氨酸（NAA）、胆碱（Cho）、肌酸（Cr）和乳酸（Lac）代谢物值，以比较组间差异，与神经认知测试评分以及与放疗剂量的相关性。
神经认知测试时的中位（范围）年龄为 18（7-26）岁。与健康对照组相比，PFT 幸存者的 Cho、Cr、NAA 和 Lac 代谢物值以及 NAA 与代谢物总和的比值显著降低（p < 0.05）。PFT 幸存者的工作记忆和程序性记忆测试评分显著降低（p < 0.004），并与 Cho 和 NAA 的中位数和最大值显著相关（0.28 <r < 0.49，p < 0.04）。除肌酸外，接受放疗和未接受放疗的幸存者之间的其他代谢物无显著差异。小脑的 MRSI 值与总剂量或该结构接受的剂量均无相关性。
研究结果显示，PFT 幸存者小脑代谢值发生变化，与记忆缺陷密切相关，提示某些代谢物可作为认知能力下降的标志物，但这需要在更大的样本量上进行验证。
