Glioma Imaging by O-(2-18F-Fluoroethyl)-L-Tyrosine PET and Diffusion-Weighted MRI and Correlation With Molecular Phenotypes, Validated by PET/MR-Guided Biopsies

Abstract

Gliomas exhibit high intra-tumoral histological and molecular heterogeneity. Introducing stereotactic biopsy, we achieved a superior molecular analysis of glioma using O-(2-18F-fluoroethyl)-L-tyrosine (FET)-positron emission tomography (PET) and diffusion-weighted magnetic resonance imaging (DWI). Patients underwent simultaneous DWI and FET-PET scans. Correlations between biopsy-derived tumor tissue values, such as the tumor-to-background ratio (TBR) and apparent diffusion coefficient (ADC)/exponential ADC (eADC) and histopathological diagnoses and those between relevant genes and TBR and ADC values were determined. Tumor regions with human telomerase reverse transcriptase (hTERT) mutation had higher TBR and lower ADC values. Tumor protein P53 mutation correlated with lower TBR and higher ADC values. α-thalassemia/mental-retardation-syndrome-X-linked gene (ATRX) correlated with higher ADC values. 1p/19q codeletion and epidermal growth factor receptor (EGFR) mutations correlated with lower ADC values. Isocitrate dehydrogenase 1 (IDH1) mutations correlated with higher TBRmean values. No correlation existed between TBRmax/TBRmean/ADC/eADC values and phosphatase and tensin homolog mutations (PTEN) or O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation. Furthermore, TBR/ADC combination had a higher diagnostic accuracy than each single imaging method for high-grade and IDH1-, hTERT-, and EGFR-mutated gliomas. This is the first study establishing the accurate diagnostic criteria for glioma based on FET-PET and DWI.

Predicting histological grade in pediatric glioma using multiparametric radiomics and conventional MRI features

“…In this study, significant differences between pHGGs and pLGGs can be observed on MRI images for restricted diffusion and ring enhancement. Restricted diffusion can provide information of the diffusion of microscopic water molecules in normal and diseased tissues 15,16 . In malignant tumors, due to the large nuclei of tumor cells, increased nuclear-to-cytoplasmic ratio, and tight cell arrangement, the intracellular and extracellular spaces are narrowed, and the diffusion of water molecules is restricted.…”

Amino Acid Tracer PET MRI in Glioma Management: What a Neuroradiologist Needs to Know

“…The 1p/19q codeletion and epidermal growth factor receptor mutations had lower ADC, and IDH1 mutations had higher TBR mean values. 25 FET-PET MR imaging predicted ATRX, MGMT, IDH1, and 1p19q mutations in 85%, 76%, 89%, and 98%, respectively. 26 Tumor Margin Delineation and Defining Tumor Extent for Radiation Therapy Planning.…”

Hybrid18F-FET PET and Perfusion MRI to Differentiate Disease Progression from Treatment-Related Changes in Malignant Brain Tumors

“…In Europe, 18 F-FET is the most frequently used amino acid tracer for brain tumor imaging, and especially in Germany, some centers have collectively performed more than 20,000 examinations because of the high clinical interest in this method (11,12). Furthermore, the increasing number of publications coming from Australia, China, India, and South Korea indicate a wide acceptance of this method (13)(14)(15)(16)(17). For 18 F-FET, approval exists in Switzerland (18) and in France (IASOglio; IASON).…”