ComBat harmonization for radiomic features in independent phantom and lung cancer patient computed tomography datasets
ComBat harmonization for radiomic features in independent phantom and lung cancer patient computed tomography datasets
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DOI：
10.1088/1361-6560/ab6177
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发表时间：
2020-01-01
影响因子：
3.5
通讯作者：
Weiss, E.
中科院分区：
文献类型：
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作者：
Mahon, R. N.;Ghita, M.;Weiss, E.
这项工作旨在评估战斗批量效应(战斗)协调算法的能力，以减少不同成像协议引起的辐射特征差异，并独立验证已发表的结果。使用32种不同的胸部成像方案对Gammex计算机断层扫描(CT)电子密度体模和类星体体模进行成像。从15个空间变化的球面轮廓中提取107个放射组学特征，这些球面轮廓在每个肺300密度、肺450密度和木质嵌入物中的1.5 cm和3 cm之间变化。使用Kolmogorov-Smirnov检验来确定特征分布的显著差异，并使用协调相关系数(CCC)来衡量作战协调前后每个协议变化类别(KVP、音调等)的特征的重复性。使用Benjamini-Hochberg-Yekutieli程序对多次比较的P值进行校正。最后，将战斗算法应用于人体受试者数据，使用6种不同的胸部成像方案，共135名患者。采用未照射肺(2 Cm)和椎骨(1 Cm)的球形轮廓进行放射学特征提取。战斗协调将来自显著不同版本的功能的百分比降低到0%-2%，或在所有协议变体中保留0%，用于LUNG300、LUNG450和木质插件。对于人体受试者数据，战斗协调性将显著不同特征的百分比从骨骼的0%-59%和肺的0%-19%降低到两者的0%。这项工作验证了以前发表的结果，并表明作战协调是协调从不同成像协议提取的放射性特征以允许在大型多机构数据集中进行比较的有效手段。通过为战斗算法提供要保护的临床或生物变量，可以明确地保存生物变异。应测试作战协调对预测模型的影响。
This work seeks to evaluate the combatting batch effect (ComBat) harmonization algorithm's ability to reduce the variation in radiomic features arising from different imaging protocols and independently verify published results. The Gammex computed tomography (CT) electron density phantom and Quasar body phantom were imaged using 32 different chest imaging protocols. 107 radiomic features were extracted from 15 spatially varying spherical contours between 1.5 cm and 3 cm in each of the lung300 density, lung450 density, and wood inserts. The Kolmogorov-Smirnov test was used to determine significant differences in the distribution of the features and the concordance correlation coefficient (CCC) was used to measure the repeatability of the features from each protocol variation class (kVp, pitch, etc) before and after ComBat harmonization. P-values were corrected for multiple comparisons using the Benjamini-Hochberg-Yekutieli procedure. Finally, the ComBat algorithm was applied to human subject data using six different thorax imaging protocols with 135 patients. Spherical contours of un-irradiated lung (2 cm) and vertebral bone (1 cm) were used for radiomic feature extraction. ComBat harmonization reduced the percentage of features from significantly different distributions to 0%-2% or preserved 0% across all protocol variations for the lung300, lung450 and wood inserts. For the human subject data, ComBat harmonization reduced the percentage of significantly different features from 0%-59% for bone and 0%-19% for lung to 0% for both. This work verifies previously published results and demonstrates that ComBat harmonization is an effective means to harmonize radiomic features extracted from different imaging protocols to allow comparisons in large multi-institution datasets. Biological variation can be explicitly preserved by providing the ComBat algorithm with clinical or biological variables to protect. ComBat harmonization should be tested for its effect on predictive models.