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Glioblastoma = Grade IV glioma
FLAIR
T1
Glioblastoma
T1 + Gd
Glioblastoma
T1 + Gd
FLAIR + Gd
T2
Major problems
•
True extent of tumour
–
Oedema or Tumor?
–
Tumour in seemingly normal brain tissue?
•
Heterogeneity of tumours
–
Grade III components without BBB disturbance
–
BBB disturbance or neovascular changes?
•
Treatment-induced changes
–
T2 hyperintensities
–
BBB disturbance
True extent of tumour
•
Gliomas:
–
Grade II: Everything that is T2 hyperintense is tumour!
–
Grade III and IV:
»
GTV: Contrast-enhancing area
»
T2-hyperintensities: Grade II components plus
edema -> CTV
»
Tumour to be expected even in seemingly normal
brain
•
Metastases:
–
Tumor confined to contrast-enhancing area
–
T2 hyperintensities are oedema!
•
Lymphoma:
–
Is a generalised CNS disease
Some little helpers...
•
Dynamic contrast-enhanced T1w imaging
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Malignant and vital foci
•
Dynamic contrast-enhanced
susceptibiltity imaging
–
Malignant foci in non-enhancing gliomas
•
Spectroscopy
–
Malignant and vital foci
–
DD tumor vs. Oedema
•
PET with 18-FDG, 18-FET, or 11-C-
Methionine
–
Metabolically active tumour