The predictive capacity of apparent diffusion coefficient (ADC) in response assessment of brain metastases following radiation
The predictive capacity of apparent diffusion coefficient (ADC) in response assessment of brain metastases following radiation
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DOI：
10.1007/s10585-016-9778-x
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发表时间：
2016-03-01
影响因子：
4
通讯作者：
Sahgal, Arjun
中科院分区：
文献类型：
--
作者：
Jakubovic, Raphael;Zhou, Stephanie;Sahgal, Arjun
目的探讨表观扩散系数(ADC)作为脑转移瘤放射反应生物标志物的预测能力。对42例接受立体定向放射外科或全脑放射治疗的患者的70个脑转移瘤分别在基线、治疗后1周和1个月进行弥散加权磁共振成像。通过将ADC测量值与基线ADC进行归一化来计算转移瘤的平均和中位数相对ADC。在治疗后一年，或最后一次可用的MRI随访时，容量标准决定了最终的肿瘤反应状态。使用单变量和多变量分析来说明与1周和1个月的肿瘤反应相关的因素。广义估计方程模型考虑了每个受试者的多个肿瘤。通过受试者操作员特征分析和Youden指数确定区分应答者和无应答者的最佳阈值以及敏感性和特异度。在1周和1个月时，较低的相对ADC值区分了应答者和无应答者(P<；0.05)。1周时的最佳反应界值为1.060，敏感度为75.0%，特异度为56.3%。以1个月为界值为0.971，敏感度和特异度分别为70.0%和68.8%。多变量一般估计方程分析表明，无放射治疗史[优势比(OR)0.211和0.137，P=0.033和0.0177]，1周和1个月的中位相对ADC值较低(OR 0.619和0.694，P=0.0036和0.005)是肿瘤反应的预测因素。放射治疗后1周和1个月的相对ADC值较低，可区分有反应者和无应答者，有望成为早期放射反应的生物标志物。
To investigate the predictive capacity of the apparent diffusion coefficient (ADC) as a biomarker of radiation response in brain metastases. Seventy brain metastases from 42 patients treated with either stereotactic radiosurgery or whole brain radiotherapy were imaged at baseline, 1 week, and 1 month post-treatment using diffusion-weighted MRI. Mean and median relative ADC for metastases was calculated by normalizing ADC measurements to baseline ADC. At 1 year post-treatment, or last available follow-up MRI, volume criteria determined final tumour response status. Uni- and multivariate analysis was used to account for factors associated with tumour response at 1 week and 1 month. A generalized estimating equations model took into consideration multiple tumours per subject. Optimal thresholds that distinguished responders from non-responders, as well as sensitivity and specificity were determined by receiver operator characteristic analysis and Youden's index. Lower relative ADC values distinguished responders from non-responders at 1 week and 1 month (P < 0.05). Optimal cut-off values for response were 1.060 at 1 week with a sensitivity and specificity of 75.0 and 56.3 %, respectively. At 1 month, the cut-off was 0.971 with a sensitivity and specificity of 70.0 and 68.8 %, respectively. A multivariate general estimating equations analysis identified no prior radiation [odds ratio (OR) 0.211 and 0.137, P = 0.033 and 0.0177], and a lower median relative ADC at 1 week and 1 month (OR 0.619 and 0.694, P = 0.0036 and 0.005), as predictors of tumour response. Lower relative ADC values at 1 week and 1 month following radiation distinguished responders from non-responders and may be a promising biomarker of early radiation response.