MRI evaluation of the effects of whole brain radiotherapy on breast cancer brain metastasis
MRI evaluation of the effects of whole brain radiotherapy on breast cancer brain metastasis
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DOI：
10.1080/09553002.2019.1554920
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发表时间：
2018-12-06
影响因子：
2.6
通讯作者：
Zhao, Dawen
中科院分区：
文献类型：
--
作者：
Crowe, William;Wang, Lulu;Zhao, Dawen
目的：通过纵向磁共振成像（MRI）评估全脑放疗（WBRT）后脑转移瘤的早期变化。材料与方法：使用7 T系统，在每天3次4戈伊WBRT分次之前和之后24小时，对乳腺癌MDA-MD 231-Br小鼠模型中的脑转移进行MRI检查。除解剖MRI外，还应用扩散加权（DW）MRI和动态对比增强（DCE）MRI分别研究细胞毒效应和血肿瘤屏障（BTB）通透性变化。结果如下：治疗前，高分辨率T2加权图像显示高信号多灶性病变，其中许多（约50%）在T1加权对比图像上没有增强，表明脑转移瘤中的BTB完好无损。虽然没有观察到新病变数量的差异，但WBRT治疗的肿瘤显著小于假手术对照（p <0.05）。DW MRI检测到WBRT肿瘤的表观扩散系数（ADC）显著增加（p <0.05），这与凋亡细胞的caspase 3染色升高相关。许多病灶在WBRT后仍无增强。然而，定量DCE MRI分析显示，尽管存在显著的空间异质性，但WBRT中的渗透性参数K-transs显著高于假手术组（p <0.05）。结论：MRI允许对WBRT诱导的BTB渗透性变化进行非侵入性评估，这可能为潜在的联合治疗提供有用的信息。
Purpose: To assess early changes in brain metastasis in response to whole brain radiotherapy (WBRT) by longitudinal Magnetic Resonance Imaging (MRI). Materials and methods: Using a 7T system, MRI examinations of brain metastases in a breast cancer MDA-MD231-Br mouse model were conducted before and 24 hours after 3 daily fractionations of 4 Gy WBRT. Besides anatomic MRI, diffusion-weighted (DW) MRI and dynamic contrast-enhanced (DCE) MRI were applied to study cytotoxic effect and blood-tumor-barrier (BTB) permeability change, respectively. Results: Before treatment, high-resolution T2-weighted images revealed hyperintense multifocal lesions, many of which (similar to 50%) were not enhanced on T1-weighted contrast images, indicating intact BTB in the brain metastases. While no difference in the number of new lesions was observed, WBRT-treated tumors were significantly smaller than sham controls (p < .05). DW MRI detected significant increase in apparent diffusion coefficient (ADC) in WBRT tumors (p < .05), which correlated with elevated caspase 3 staining of apoptotic cells. Many lesions remained non-enhanced post WBRT. However, quantitative DCE MRI analysis showed significantly higher permeability parameter, K-trans, in WBRT than the sham group (p < .05), despite marked spatial heterogeneity. Conclusions: MRI allowed non-invasive assessments of WBRT induced changes in BTB permeability, which may provide useful information for potential combination treatment.