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.

除了威胁生命的诊断的负担外，癌症患者还面临着癌症治疗带来的不利副作用的困扰。化学疗法已经与一系列认知障碍以及大脑结构和功能的改变联系在一起（“ chemobrain”）。在这篇综述中，我们总结了现有证据，这些证据评估了在纵向设计中使用基于结构和功能性MRI的技术评估的化学疗法对认知功能和大脑的影响。

这篇评论遵循的最新PRISMA指南使用了Embase，Medline，PsychINFO，Scopus和Web of Science数据库，日期限制为2012年至2017年。14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）; （ii）使用化学疗法治疗癌症；（iii）行为和基于大脑的结果的事前评估；（iv）以英文撰写的摘要。使用Cohen的d或z评分，评估了回顾性研究中主观和客观认知障碍的影响大小。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或效应大小的百分比。使用平方的相关系数获得了大脑变化和认知变化之间的相关强度。

展示了中小型效果吗？对注意力，处理速度，言语记忆和执行控制进行单独测试；自我报告调查问卷的影响大小为中等。神经影像学数据显示，额叶，顶叶和颞叶区域癌症患者的灰质密度降低。在涉及（前）额叶，顶叶，枕叶，颞叶和小脑区域的功能网络中，癌症的大脑功能（大脑激活和脑血流量）发生了变化。扩散加权MRI的数据表明，白质完整性降低，涉及上纵筋膜，call体，大钳和电晕放射，并改变了整个大脑网络的结构连接性。最后，

尽管MRI是检测“化学障碍”中纵向脑部变化的有力工具，但其潜在的生物学机制仍不清楚。该领域的持续工作将有望检测出MRI指标，将其用作生物标志物，以帮助指导各个癌症患者水平的认知治疗。