18F-FDG PET/CT for Monitoring Treatment Responses to the Epidermal Growth Factor Receptor Inhibitor Erlotinib

• DOI: 10.2967/jnumed.111.095257
• Publication Date: 2011-11-01T19:14:17Z
• Authors: Matthias R. Benz; Ken Herrmann; Franziska Walter; Edward B. Garon; Karen L. Reckamp; Robert Figlin; Michael E. Phelps; Wolfgang A. Weber; Johannes Czernin; Martin S. Allen-A...
• Keywords: Adult; Aged, 80 and over; Male; Lung Neoplasms; Biological Transport; Middle Aged; Multimodal Imaging; Survival Analysis; 3. Good health; ErbB Receptors; Erlotinib Hydrochloride; 03 medical and health sciences; 0302 clinical medicine; Fluorodeoxyglucose F18; Carcinoma, Non-Small-Cell Lung; Positron-Emission Tomography; Disease Progression; Quinazolines; Humans; Female; Protein Kinase Inhibitors; Aged; Neoplasm Staging

Response rates of unselected non-small cell lung cancer (NSCLC) patients to the epidermal growth factor receptor inhibitor erlotinib are low and range from 10% to 20%. Early response assessments are needed to avoid costs and side effects of inefficient treatments. Here we determined whether early changes in tumor uptake of (18)F-FDG can predict progression-free and overall survival in NSCLC patients who are treated with erlotinib.Twenty-two patients (6 men, 16 women; mean age ± SD, 64 ± 13 y) with stage III or stage IV NSCLC who received erlotinib treatment were enrolled prospectively. (18)F-FDG PET/CT was performed before the initiation of treatment (n = 22), after 2 wk (n = 22), and after 78 ± 21 d (n = 11). Tumor maximum standardized uptake values were measured for a maximum of 5 lesions for each patient. Tumor responses were classified using modified PET Response Criteria in Solid Tumors (use of maximum standardized uptake values). Median overall survival by Kaplan-Meier analysis was compared between groups using a log-rank test.The overall median time to progression was 52 d (95% confidence interval, 47-57 d). The overall median survival time was 131 d (95% confidence interval, 0-351 d). Patients with progressive metabolic disease on early follow-up PET showed a significantly shorter time to progression (47 vs. 119 d; P < 0.001) and overall survival (87 vs. 828 d; P = 0.01) than patients classified as having stable metabolic disease or partial or complete metabolic response.These data suggest that (18)F-FDG PET/CT performed early after the start of erlotinib treatment can help to identify patients who benefit from this targeted therapy.