[PET in gliomas. Overview of current studies].

Gliomas which represent 30% of intracranial tumours are morphologic lesions and therefore CT and MRI are the first line diagnostic procedures with MRI giving better soft tissue resolution and permitting additional functional information. These mainly morphologic imaging modalities yield only restricted information on grade of malignancy, on infiltration into and effects on surrounding brain tissue, on differentiation between necrotic and recurrent tumour, on prognosis and on efficacy of treatment. Information on these important issues for patient management can be obtained by PET-studies of glucose metabolism with FDG, of aminoacid-uptake and protein synthesis with 11C-methionin, 18F-fluorethyltyrosin and 18F-fluor-deoxyphenylalanin and of proliferation by 18F-deoxythymidin. With the increasing availability of 18F-tracers PET has obtained wider spread clinical application. In all these applications a coregistration with morphologic imaging should be obtained, and for that purpose hybrid installations (PET-MR) are already being used.