Multimodal MRI and PET Imaging of Glioblastoma

MRI of the brain and spine were acquired on a Siemens MAGNETOM Verio 3.0 Tesla scanner. Pre, post, dynamic contrast enhanced, dynamic susceptibility contrast, gadolinium T1-weighted, diffusion and T2-weighted sequences were acquired. Tumor foci were measured on axial T1 multi-planar reconstruction (MPR)-weighted images obtained after the administration of MultiHance (gadobenate dimeglumine). Response assessment was recorded using the modified RANO criteria for GBM. Imaging with ¹⁸F-fluorodeoxyglucose was performed using a GE Discovery DST HP60 PET-CT scanner (70 cm axial field of view, slice thickness 3.75 mm). Maximal standardized uptake values were obtained utilizing Vital Images Vitrea version 6.7.2 software. For the calculation of contrast-enhancing tumor volumes, T2-weighted, T2-weighted Fluid Attenuated Inversion Recovery, T1-weighted pre- and post- contrast images were coregistered and resampled to 1 mm × 1 mm × 3 mm voxel sizes using BraTumIA software^{50 (link)}. The registered, non-skull-stripped images were then imported into ITK-SNAP (v3.8.0) for segmentation^{51 (link)}. Trained readers generated initial masks of the tumor volumes with final review and volume selection by a radiologist with over 10 years of experience in neuroradiology.