Tumor perfusion using first-pass F-18 FDG PET images.

Many reports in the literature have focused on FDG PET imaging at conventional (60 minutes after injection) or delayed (several hours after injection) intervals, which exploits increased glycolysis in tumors for diagnosis. However, in rapidly growing tumors, accelerated glycolysis is, among other factors, mediated by hypoxia and poor perfusion. Interestingly, first-pass (0-2 minutes after injection) FDG PET images were shown to provide an index of perfusion. Here, we illustrate that tracer uptake by various (parts of) tumors is discrepant between first-pass and conventional PET images, probably reflecting the direct control of glucose transporter overexpression by hypoxia, resulting from poor perfusion (Warburg's hypothesis).