Quantitative integration of radiomic and genomic data improves survival prediction of low-grade glioma patients

Glioma is the most common and most serious form of brain tumors that affects adults. Accurate prediction of survival and phenotyping of low-grade glioma (LGG) patients at high or low risk are the key to achieving precision diagnosis and treatment. This study is aimed to integrate both magnetic resonance imaging (MRI) data and gene expression data to develop a new integrated measure that represents a LGG patient's disease-specific survival (DSS) and classify subsets of patients at low and high risk for progression to cancer. We first construct the gene regulatory network by using gene expression data. We obtain twelve network modules and identify eight image biomarkers by using the Cox regression model with MRI data. Furthermore, correlation analysis between gene modules and image features identify four radiomic features. The least absolute shrinkage and selection operator (Lasso) method is applied to predict these image features with gene expression data when lacking MRI data or image segmentation technology. Furthermore, the support vector machine (SVM)-based recursive feature elimination method has been established to predict DSS using gene signatures. Finally, 4 image signatures and 43 gene signatures are recognized to be associated with the patient's prognosis. An integrated measure for combining image and gene signatures is obtained through the PSO algorithm. The concordance index (C-index) and the time-dependent receiver operating characteristic (ROC) analysis are used to evaluate prediction accuracy. The C-index obtained for this integrated measure is 0.8071 and the area under the curve (AUC) of the ROC curve is 0.79, which are higher than any other single features. The 72.1% accuracy of classification of patients is better than the accuracy associated with the published work. These results demonstrate that integration analysis of radiomic and genomic data can improve the accuracy of the prediction of survival for lower grade gliomas.