[en] Objective: To determine the prognostic value of standardized uptake value (SUV) of fluorodeoxyglucose(FDG) by positron emission tomography and computed tomography (PET-CT) in non-small cell lung cancer (NSCLC). Methods: Forty-eight patients (39 male, 9 female) with stage III NSCLC were reviewed. All patients had at least two repeated FDG PET-CT scans either before and after therapy and the maximum standardized uptake value (SUV_max) of the primary lung lesion was calculated. Results: Of the 45 eligible patients, after a median follow-up of 22.5 months (rang, 13 to 35 months), 24 patients had local and regional recurrence or metastasis and 21 remain disease-free. The mean SUV_max of patients who had local recurrence or metastasis before and after treatment was 12.30 ± 3.17 and 5.35 ± 2.29, respectively. The mean SUV_max of patients who had no local recurrence or metastasis before and after treatment was 8.46 ± 3.00 and 2.82 ± 0.63, respectively. Significant differences (t_before=4. 15, P_before< 0.01; P_after=4.88, P_after<0.01) in SUV_max were observed either before and after treatment. However, the percent change of SUV_max between pretreatment and post-treatment were not significantly different (t=1.99, P> 0.05). Using the SUVbefore of 9.0 yielded 92% sensitivity, 62% specificity, 73% positive predictive value and 87% negative predictive value in predicting regional recurrence or metastasis. While using the SUVafter of 4.3 yielded 71% sensitivity, 100% specificity, 100% positive predictive value and 72% negative predictive value. Conclusions: PET-CT may have the potentials to predict response to therapy and the SUV_max is a significant predictor for recurrent or metastasis in patients of NSCLC. (authors)