Fig. 2.

MRI and 18F-FET PET findings in a radiation-induced lesion after focused high dose radiotherapy (Patient nr. 18). A ring-like contrast enhancement in the T1-weighted images (a), as well as an extensive edema in the T2-weighted images is seen (b). Both a marginal focal 18F-FET uptake (TBRmax 1.4, TBRmean 1.3) and increasing TACs can be observed in static and dynamic PET analysis (c, d)