Hypoxia is important in the biology of glioma in humans. Positron emission tomography/computed tomography (PET/CT) with a hypoxia tracer offers a noninvasive method to differentiate individual tumor biology and potentially modify treatment for patients with malignancies. The purpose of this study was to determine whether hypoxia, as measured by fluorine-18 fluoroerythronitroimidazole (18F-FETNIM) PET/CT, was associated with tumor grade, overall survival (OS), and immunohistochemical features related to hypoxia, proliferation, angiogenesis, and the invasion of gliomas.
Twenty-five patients with gliomas in whom gross maximal resection could be safely attempted were analyzed. All patients underwent 18F-FETNIM PET/CT studies before surgery. The maximum standardized uptake value (SUVmax) was obtained from the PET images of tumor tissues. Tumor specimens were stereotactically obtained for the immunohistochemical staining of hypoxia-inducible factor-1 alpha (HIF-1α), Ki-67, vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9).
A correlation between the SUVmax and glioma grade was found (r = 0.881, P < 0.001). The SUVmax was significantly correlated with the expression of HIF-1α, Ki-67, VEGF, and MMP-9 (r = 0.820, 0.747, 0.606, and 0.727; all P < 0.001). Patients with a high SUVmax had significantly worse 3-year OS than those with a low SUVmax (24.4% vs. 82.1%, P = 0.003).
18F-FETNIM PET/CT provides an excellent noninvasive assessment of hypoxia in glioma. It can be used to understand the mechanisms by which hypoxia affects the OS of glioma patients.