Radiomics analysis of non-enhancing lesions after Bevacizumab administration in recurrent glioblastoma

Motivation: Identifying non-contrast-enhancing tumor (nCET) in glioblastoma (GBM) is crucial for surgical treatment. However, T2/FLAIR images are unable to reliably distinguish nCET from vasogenic edema (VE). Goal(s): To develop an MRI-based method to identify nCET via radiomic features on areas where CET transformed to nCET after BEV administration. Approach: Radiomic features were analyzed in an exploratory cohort under BEV treatment (n=24) and a validation cohort who underwent 11C-methionine positron emission tomography (n=23). Results: A combination of three imaging features distinguished nCET from VE (AUC=0.91) with high positive predictive accuracy. Reconstructed MRI images also provided reasonable nCET visualization in newly diagnosed GBMs. Impact: Radiomic features of lesion where CET transformed into nCET after BEV administration may provide valuable information in predicting nCET in GBM.