Striatal "Function-Metabolism" Mismatch on F-18 FDG/F-18 FDOPA PET/CT

Decrease in gray matter metabolism following cranial irradiation has been documented, but the functional relevance of this finding has not been documented. This case of "function-metabolism" mismatch in the striatum following radiation for a grade III frontoparietal glioma demonstrates that the down-regulation of glucose metabolism as demonstrated by F-18 fluorodeoxyglucose positron emission tomography/computed tomography is associated with preservation of presynaptic dopaminergic function by the striatal neurons which was demonstrated on a correlative L-3,4-dihydroxy-6-F-18-flurophenylalanine (F-18 FDOPA) study. The reversibility of this down-regulation is demonstrated in a follow-up scan further proving that there is no neurodegeneration involved.