Overall Survival Prediction for Glioblastoma on Pre-treatment MRI Using Robust Radiomics and Priors.

Patients with Glioblastoma multiforme (GBM) have a very low overall survival (OS) time, due to the rapid growth an invasiveness of this brain tumor. As a contribution to the overall survival (OS) prediction task within the Brain Tumor Segmentation Challenge (BraTS), we classify the OS of GBM patients into overall survival classes based on information derived from pre-treatment Magnetic Resonance Imaging (MRI). The top-ranked methods from the past years almost exclusively used shape and position features. This is a remarkable contrast to the current advances in GBM radiomics showing a benefit of intensity-based features. This discrepancy may be caused by the inconsistent acquisition parameters in a multi-center setting. In this contribution, we test if normalizing the images based on the healthy tissue intensities enables the robust use of intensity features in this challenge. Based on these normalized images, we test the performance of 176 combinations of feature selection techniques and classifiers. Additionally, we test the incorporation of a sequence and robustness prior to limit the performance drop when models are applied to unseen data. The most robust performance on the training data (accuracy: 0.52 +/- 0.09) was achieved with random forest regression, but this accuracy could not be maintained on the test set.