School of Psychology, Faculty of Health Sciences, Australian Catholic University, 115 Victoria Parade, Melbourne VIC 3065, Australia.
School of Psychology, Faculty of Health Sciences, Australian Catholic University, 115 Victoria Parade, Melbourne VIC 3065, Australia.
Neurosci Biobehav Rev. 2018 Sep;92:304-317. doi: 10.1016/j.neubiorev.2018.05.019. Epub 2018 May 20.
In addition to the burden of a life-threatening diagnosis, cancer patients are struggling with adverse side-effects from cancer treatment. Chemotherapy has been linked to an array of cognitive impairments and alterations in brain structure and function ("chemobrain"). In this review, we summarized the existing evidence that evaluate the changes in cognitive functioning and brain with chemotherapy, as assessed using structural and functional MRI-based techniques in a longitudinal design. This review followed the latest PRISMA guidelines using Embase, Medline, PsychINFO, Scopus, and Web of Science databases with date restrictions from 2012 to 2017. Fourteen research articles met the key inclusion criteria: (i) the studies involved adult cancer patients (mean age ≥ 18); (ii) the use of chemotherapy in the treatment of cancer; (iii) pre-post assessment of behavioral and brain-based outcomes; and (iv) abstracts written in English. Effect sizes of subjective and objective cognitive impairments from the reviewed studies were estimated using Cohen's d or z-scores. We calculated percentage of mean change or effect sizes for main neuroimaging findings when data were available. Strength of the correlations between brain alterations and cognitive changes was obtained using squared correlation coefficients. Small to medium effect sizes were shown? on individual tests of attention, processing speed, verbal memory, and executive control; and medium effect sizes on self-report questionnaires. Neuroimaging data showed reduced grey matter density in cancer patients in frontal, parietal, and temporal regions. Changes in brain function (brain activation and cerebral blood flow) were observed with cancer across functional networks involving (pre)frontal, parietal, occipital, temporal, and cerebellar regions. Data from diffusion-weighted MRI suggested reduced white matter integrity involving the superior longitudinal fasciculus, corpus callosum, forceps major, and corona radiate, and altered structural connectivity across the whole brain network. Finally, we observed moderate-to-strong correlations between worsening cognitive function and morphological changes in frontal brain regions. While MRI is a powerful tool for detection of longitudinal brain changes in the 'chemobrain', the underlying biological mechanisms are still unclear. Continued work in this field will hopefully detect MRI metrics to be used as biomarkers to help guide cognitive treatment at the individual cancer patient level.
除了危及生命的诊断带来的负担外，癌症患者还在与癌症治疗的不良反应作斗争。化疗与一系列认知障碍以及大脑结构和功能的改变有关（“化疗脑”）。在这篇综述中，我们总结了现有的证据，这些证据评估了使用基于结构和功能 MRI 的技术进行纵向设计时，化疗对认知功能和大脑的变化。本综述遵循最新的 PRISMA 指南，使用 Embase、Medline、PsychINFO、Scopus 和 Web of Science 数据库，限制日期为 2012 年至 2017 年。十四篇研究文章符合关键纳入标准：（i）研究涉及成年癌症患者（平均年龄≥18 岁）；（ii）使用化疗治疗癌症；（iii）对行为和基于大脑的结果进行前后评估；（iv）摘要用英语书写。使用 Cohen 的 d 或 z 分数估计来自综述研究的主观和客观认知障碍的效应大小。当数据可用时，我们计算了主要神经影像学发现的平均变化百分比或效应大小。使用平方相关系数获得大脑改变与认知变化之间相关性的强度。在注意力、处理速度、言语记忆和执行控制等单项测试中，显示出小到中等的效应大小；在自我报告问卷中，显示出中等的效应大小。神经影像学数据显示，癌症患者的额、顶和颞叶区域的灰质密度降低。在涉及前额叶、顶叶、枕叶、颞叶和小脑区域的功能网络中观察到大脑功能（大脑激活和脑血流）的变化。来自弥散加权 MRI 的数据表明，涉及上纵束、胼胝体、内囊、辐射冠和放射冠的白质完整性降低，以及整个大脑网络的结构连接改变。最后，我们观察到认知功能恶化与额叶大脑区域的形态变化之间存在中度到强相关性。虽然 MRI 是检测“化疗脑”中纵向大脑变化的有力工具，但潜在的生物学机制仍不清楚。该领域的持续研究有望检测到 MRI 指标，作为帮助指导个体癌症患者认知治疗的生物标志物。
