Abstract #4814

Dynamic Contrast-Enhanced T1 -Weighted Perfusion MRI Differentiates Tumor Recurrence from Radiation Necrosis: Relative Cerebral Blood Volume Measurements and FDG-PET Validation

Vibeke Andre Larsen¹, Helle Juhl Simonsen², Ian Law³, Henrik Pedersen², Henrik BW Larsson², Adam Espe Hansen²

¹Dept. of Radiology, Glostrup Hospital, University of Copenhagen, Glostrup, Denmark; ²Functional Imaging Unit, University of Copenhagen, Glostrup Hospital, Glostrup, Denmark; ³PET and Cyclotron Unit, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark

The use of perfusion MRI for tumor characterization is complicated by the blood brain barrier deficiency. This preliminary study provides evidence that dynamic contrast enhanced T₁ weighted perfusion imaging can distinguish radiation-induced necrosis from tumor recurrence. We studied 9 patients after radiation treatment for gliomas and the results were validated with the FDG-PET gold standard. For 10 contrast enhancing lesions, 2 metabolically inactive lesions had relative cerebral blood volume (rCBV) of less than 1.7, whereas 8 active lesions had rCBV greater than 2.0.