The use of some different positron emission tomography (PET) imaging agents is expected to lead the useful way for applications toward efficient malignancy grading and diagnosis of brain tumors. In this study, the usefulness of 18 F-fluorodeoxyglucose (FDG), 11 C-methionine (MET), 18 F-fluoro-3’-deoxy-3’-L-fluorothymidine (FLT) and 18 F-fluoromisonidazole (FMISO) PET images was retrospectively reviewed. In malignant lymphomas, tumor FDG uptake was significantly higher with accelerated phosphorylation activity compared with that observed in the normal cortex. PET studies using MET and FLT are useful for tumor detection in gliomas. MET transport may be increased by an increased number of microvessels combined with a higher density or activity of LAT1 in the tumor endothelial cells in high-grade gliomas. FLT uptake in the tumor is also significantly related to transport through the disrupted BBB, but not through phosphorylation activity. The viable hypoxic tissue assessed by FMISO PET was related to the neovascularization in glioblastomas. FMISO PET appears to be a suitable biomarker for predicting a highly malignant tumor in patients with glioma. PET imaging is a noninvasive modality that is useful in management of brain tumors.
