Introduction: The aim of this study was to compare glucose metabolism and hypoxia using 18F- fluorodeoxyglucose (18F-FDG) and 18F-fluoroerythronitroimidazole (18F-FETNIM) positron emission tomography (PET) and investigate their prognostic role on survival in patients with locally advanced non-small-cell lung cancer (NSCLC).
Patients and methods: Twenty-six patients with NSCLC were imaged with 18F-FETNIM PET/computed tomography (CT), and 11 cases also with 18F-FDG PET/CT imaging among those with significant 18F-FETNIM uptake, a few days before any chemo/adiation therapy. The maximum standardized uptake value (SUVmax) was used to depict 18F-FDG uptake, and hypoxic volume (HV) and tumor:blood ratio (T/Bmax) were used to quantify hypoxia. Overall survival (OS) after treatment was selected as the endpoint of the study.
Results: Twenty-two patients (84.6%) had significant 18F-FETNIM uptake in the primary tumor. The correlations between the overall tumor SUVmax of 18F-FDG and HV, T/Bmax ratio of 18F-FENTIM in 11 patients were small and without significant difference. In univariate analyses, log-rank tests were used to compare Kaplan-Meier survival curves. 18F-FETNIM T/Bmax ratio and HV were strong predictors for OS, and 18F-FDG uptake of the primary lesions did not have a significant relationship with survival. In multivariate survival analysis, only 18F-FETNIM T/Bmax ratio was found to be an independent prognostic factor.
Conclusion: Imaging using both 18F-FETNIM and 18F-FDG appears to be beneficial in the evaluation of solid tumors. 18F-FETNIM imaging provides us with a valuable method to detect tumor hypoxia and predict OS. These preliminary results warrant validation in larger trials.