MET PET from disease onset (a) to disease progression (e) of a patient with LGGs in the left hemisphere, showing a gradual increase in hot-spot activity during progressive disease. This patient received radiotherapy between the first (a) and second PET investigation (b), and chemotherapy between the second (b) and third (c) PET investigation. MET PET was performed at approximately 6 months intervals from the time point of disease onset.