Multimodal imaging of patients with gliomas confirms 11C-MET PET as a complementary marker to MRI for noninvasive tumor grading and intraindividual follow-up after therapy

Abstract

The value of combined L-(methyl-[11C]) methionine positron-emitting tomography (MET-PET) and magnetic resonance imaging (MRI) with regard to tumor extent, entity prediction, and therapy effects in clinical routine in patients with suspicion of a brain tumor was investigated. In n = 65 patients with histologically verified brain lesions n = 70 MET-PET and MRI (T1-weighted gadolinium-enhanced [T1w-Gd] and fluid-attenuated inversion recovery or T2-weighted [FLAIR/T2w]) examinations were performed. The computer software "visualization and analysis framework volume rendering engine (Voreen)" was used for analysis of extent and intersection of tumor compartments. Binary logistic regression models were developed to differentiate between World Health Organization (WHO) tumor types/grades. Tumor sizes as defined by thresholding based on tumor-to-background ratios were significantly different as determined by MET-PET (21.6 ± 36.8 cm3), T1w-Gd-MRI (3.9 ± 7.8 cm3), and FLAIR/T2-MRI (64.8 ± 60.4 cm3; P