Twenty-two patients with advanced non-small-cell lung cancer (NSCLC) received first-line treatment, and (F-18-FDG) positron emission tomography (PET) and computed tomography (CT) were performed before and after therapy. A trend was shown on FDG-PET for responders to treatment after 2 weeks in terms of progression-free survival (PFS) and overall survival (OS). Early metabolic responders had a better outcome. Background: This study aimed to demonstrate that patients who exhibit a tumor metabolic response to first-line chemotherapy seen on FDG-PET and computed tomography (CT) would survive longer than those who did not show such a response, comparing this evaluation with the morphologic response seen on CT. Patients and Methods: Images were acquired in 22 consecutive patients with advanced non-small-cell lung cancer (NSCLC) randomized to receive carboplatin/paclitaxel/sorafenib or placebo. FDG-PET was performed within 4 weeks before (PET1) and 2 weeks after starting treatment (PET2). Similarly, CT (CT1) was performed at baseline and then every 2 cycles (6 weeks) during treatment (CT2). Responders and nonresponders were identified with FDG-PET, and metabolic response was then compared with morphologic changes detected by spiral CT. Results: Twenty-one of 22 patients completed this study. In terms of progression-free survival (PFS) (45 vs. 22.2 weeks) and overall survival (OS) (77 vs. 47.7 weeks), we observed a trend that was not statistically significant for patients whose response after 2 weeks of treatment was seen on FDG-PET (P = .22 for PFS; P = .15 for OS). Conclusion: Patients with advanced NSCLC who had a positive outcome, as evidenced by prolonged survival, were those who showed a tumor metabolic response seen on FDG-PET. Clinical Lung Cancer, Vol. 14, No. 3, 230-7 (C) 2013 Elsevier Inc. All rights reserved.