For example, a number of established PET tracers like O-(2-[18F]fluoroethyl)tyrosine ([18F]FET) or 6-[18F]fluoro-3,4-dihydroxyphenylalanine ([18F]FDOPA) have been successfully used to infer the IDH mutation status in gliomas [18,19,20,21,22]. This evidence concerns the gene IDH1 and central nervous system cancer.