Primary Tumor Standardized Uptake Value Measured on F18-Fluorodeoxyglucose Positron Emission Tomography Is of Prediction Value for Survival and Local Control in Non-Small-Cell Lung Cancer Receiving Radiotherapy: Meta-Analysis

Introduction:The 2-[18F]-Fluorodeoxyglucose (FDG) positron emission tomography (PET/CT) has become an imaging tool for clinical assessment of tumor, node, metastasis in non-small-cell lung cancer (NSCLC). Primary tumor maximum standardized uptake value (SUVmax) on 18F-FDG PET/CT before and after radiation therapy (RT) has been studied as a potential prognostic factor for NSCLC patients receiving radiotherapy. However, the sample sizes of most studies were small, and the results of the prediction value of SUVmax remained undetermined, which lead us to perform a meta-analysis to improve the precision in estimating its effect.Methods:We performed a meta-analysis of published literature for primary tumor SUVmax-based biomarkers of the outcome of NSCLC receiving radiotherapy. The required data for estimation of individual hazard ratios (HRs) to compare patients with a low and a high SUVmax were extracted from each publication. A combined HR was calculated by Stata statistical software (Version 11). All of the results were verified by two persons to ensure its accuracy.Results:Thirteen studies were finally included into this meta-analysis; data are available in 13 studies for pre-RT primary tumor SUVmax and in five studies for post-RT. For overall survival, the combined HR estimate was 1.05 (95% confidence interval [CI], 1.02-1.08) and 1.32 (95% CI, 1.15-1.51) for pre-RT SUVmax and post-RT SUVmax, respectively; 1.26 (95% CI, 1.05-1.52) and 2.01 (95% CI, 1.16-3.46) for local control (LC). In stereotactic body radiotherapy (SBRT) group, HR for LC was 1.11 (95% CI, 1.06-1.18) and 2.19 (95% CI, 1.34-3.60) for pre-SBRT SUVmax and post-SBRT SUVmax, respectively.Conclusion:Both pre-RT and post-RT primary tumor SUVmax can predict the outcome of patients with NSCLC treated with radiotherapy. Patients with high levels of pre-RT SUVmax seemed to have poorer overall survival and LC.