21 / 1266
METABOLIC IMAGING
PET [11C]Methionine (MET)
•
The highest uptake is observed in anaplastic oligodendrogliomas WHO grade III
•
LGG are better detected by aminoacid tracers due to increased uptake in
the absence of blood-
brain barrier damage
•
LGG: useful for differentiation from nonntumorous lesions, detection of recurrences, indication of
progressing disease
•
Can differentiate better between Recurrent tumour and Radiation Necrosis with high
sensitivity and specificity (~75%): necrosis and glioses after therapy show a
reduction of ammoniated uptake in contrast to recurrent and residual tumour growth
.
•
Deactivation of aminoacid transport is a early sign of response to chemotherapy
(Galldicks N et al Mol Imaging 2010). PET responders with a decrease of tumour
brain/ratio of >10% had a significant longer TTP and OS than patient with increase
tracer uptake after RT and CHT in GBM.