Department of Oncology, Aarhus University Hospital, Denmark.
Department of Oncology, Aarhus University Hospital, Denmark; Unit for Psychooncology and Health Psychology, Department of Psychology and Behavioral Sciences, Aarhus University, Denmark.
Radiother Oncol. 2020 Jul;148:1-7. doi: 10.1016/j.radonc.2020.03.023. Epub 2020 Mar 28.
Radiation therapy (RT) to the brain may result in cognitive impairment. The primary objective of the present study was to examine the relationship between RT dose to the hippocampus and learning and memory functions. Secondary objective was to examine relationships between doses to other brain structures and specific cognitive functions.
A cross-sectional analysis was undertaken in 78 primary brain tumour patients after RT. Cognitive function was assessed by neuropsychological tests. Test scores were standardized using normative data adjusted for age and level of education. Test-specific cognitive impairment was determined as a z-score ≤-1.5. Radiation dose to brain structures and test-specific cognitive impairment outcomes were fitted to a logistic regression model.
High RT dose to the left hippocampus was associated with impaired verbal learning and memory (p = 0.04). RT dose to the left hippocampus, left temporal lobe, left frontal lobe and total frontal lobe were associated with verbal fluency impairment (p < 0.05) and doses to the thalamus and the left frontal lobe with impaired executive functioning (p ≤ 0.03). Finally, RT dose to the brain and thalamus were associated with impaired processing speed (p ≤ 0.05).
The present study indicates that the hippocampus may be vulnerable to radiation and that high radiation doses to the left hippocampus may lead to significant verbal learning and memory impairment. High RT doses to the left hippocampus and other left side structures may result in impairments in verbal fluency, executive function, and processing speed. Validation of these findings are being undertaken in a prospective study.
脑部放射治疗（RT）可能导致认知障碍。本研究的主要目的是检验海马体 RT 剂量与学习和记忆功能之间的关系。次要目的是检验其他脑结构剂量与特定认知功能之间的关系。
对 78 名接受 RT 治疗的原发性脑肿瘤患者进行了横断面分析。认知功能通过神经心理学测试进行评估。使用针对年龄和教育程度进行调整的标准数据对测试分数进行标准化。测试特异性认知障碍定义为 z 分数≤-1.5。将脑结构的放射剂量和测试特异性认知障碍结果拟合到逻辑回归模型中。
左侧海马体高 RT 剂量与言语学习和记忆受损相关（p=0.04）。左侧海马体、左侧颞叶、左侧额叶和总额叶的 RT 剂量与言语流畅性受损相关（p<0.05），丘脑和左侧额叶的剂量与执行功能受损相关（p≤0.03）。最后，大脑和丘脑的 RT 剂量与处理速度受损相关（p≤0.05）。
本研究表明海马体可能对辐射敏感，左侧海马体高 RT 剂量可能导致明显的言语学习和记忆障碍。左侧海马体和其他左侧结构的高 RT 剂量可能导致言语流畅性、执行功能和处理速度受损。正在进行前瞻性研究以验证这些发现。
