Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University, Baltimore, Maryland.
Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University, Baltimore, Maryland.
Int J Radiat Oncol Biol Phys. 2018 Aug 1;101(5):1234-1242. doi: 10.1016/j.ijrobp.2018.04.037. Epub 2018 Apr 22.
Brain radiation is associated with functional deficits in children. The purpose of this study was to examine white matter integrity as measured by diffusion tensor imaging and associations with region-specific radiation dose and neuropsychological functioning in children treated with cranial irradiation.
A total of 20 patients and 55 age- and sex-matched controls were included in the present study. Diffusion tensor imaging and neuropsychological assessments were conducted at baseline and 6, 15, and 27 months after treatment. The neuropsychological assessment included motor dexterity, working memory, and processing speed. White matter regions were contoured, and the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were recorded for each participant. Linear mixed effects regression models were used to prospectively compare the associations among ADC, FA, radiation dose to contoured structures, and performance on the neuropsychological assessments over time.
The mean prescription dose was 44 Gy (range 12-54). Across visits, compared with the controls, the patients showed a significantly increased ADC across all selected regions and alterations in FA in the dorsal midbrain and corpus callosum (genu, splenium, body). An increased radiation dose to the genu and body of the corpus callosum was associated with alterations in ADC and FA and reduced neuropsychological performance, most notably motor speed and processing.
These prospective data suggest that subcortical white matter, especially the genu and body of the corpus callosum, could be regions with increased susceptibility to radiation-induced injury, with implications for cognitive function.
脑部放射治疗与儿童的功能缺陷有关。本研究的目的是通过弥散张量成像（DTI）检查，研究脑照射治疗的儿童的白质完整性，并探讨其与特定区域辐射剂量和神经心理学功能的相关性。
本研究共纳入 20 例患者和 55 例年龄和性别匹配的对照组。在治疗前、治疗后 6、15 和 27 个月进行弥散张量成像和神经心理学评估。神经心理学评估包括运动灵巧性、工作记忆和处理速度。对大脑白质区域进行轮廓勾画，并记录每位参与者的表观扩散系数（ADC）和各向异性分数（FA）。采用线性混合效应回归模型，前瞻性比较 ADC、FA、勾画结构的辐射剂量与神经心理学评估结果之间的相关性。
平均处方剂量为 44 Gy（范围 12-54）。与对照组相比，患者在所有选定区域的 ADC 均显著升高，且中脑背侧和胼胝体（体部、膝部）的 FA 改变。胼胝体膝部和体部的辐射剂量增加与 ADC 和 FA 的改变以及神经心理学表现的下降有关，尤其是运动速度和处理能力。
这些前瞻性数据表明，皮质下白质，特别是胼胝体的膝部和体部，可能是对辐射诱导损伤更敏感的区域，这可能对认知功能有影响。
