Role of Various Metabolic Parameters Derived From Baseline 18F-FDG PET/CT as Prognostic Markers in Non-Small Cell Lung Cancer Patients Undergoing Platinum-Based Chemotherapy.

Abstract

The aim of this study was to prospectively evaluate the role of various quantitative and semiquantitative metabolic parameters derived from dynamic and static baseline F-FDG PET/CT in prediction of overall survival (OS) in non-small cell lung cancer (NSCLC) patients who were planned to undergo platinum-based chemotherapy. Sixty patients (51 male and 9 female patients) with biopsy-proven NSCLC and mean age 59.55 ± 10.06 years who were planned to undergo platinum-based chemotherapy were enrolled in the study. Each patient underwent a baseline regional dynamic and a static whole-body F-FDG PET/CT after injecting 0.21 mCi/kg (5.18-7.77 MBq/kg) of F-FDG intravenously. Two dynamic PET/CT parameters, that is, net influx rate constant and glucose metabolic rate at 30 and 60 minutes, were evaluated. In addition, whole-body PET/CT parameters, that is, SUVmax, average SUV, tumor-to-background ratio, metabolic tumor volume (MTV), total lesion glycolysis (TLG) of the primary tumor, and MTV and TLG of whole-body tumor lesions, were evaluated. Best possible cutoffs for all parameters were calculated using receiver operating characteristic curve analysis. Survival analysis was performed using log-rank test, Kaplan-Meier curves, and Cox proportional hazards model to determine the prognostic markers for OS. The median follow-up period was 4.4 months (range, 8 days to 15.9 months). In univariate analysis, the 4 static whole-body PET/CT parameters, that is, MTV, TLG, and MTV and TLG of whole-body tumor lesions, were found to be significantly associated with OS with cutoff values of 120, 800, 160, and 1350 cm and hazard ratios of 3.64 (P = 0.001), 3.35 (P = 0.002), 2.51 (P = 0.019), and 2.69 (P = 0.008), respectively. In multivariate survival analysis, MTV was found to be an independent prognostic marker for OS. Baseline MTV and TLG evaluated from primary tumor as well as the whole-body tumor lesions are reliable prognostic markers of OS in NSCLC patients undergoing platinum-based chemotherapy. However, other baseline whole-body PET/CT parameters (SUVmax, average SUV, and tumor-to-background ratio) and dynamic PET/CT parameters (net influx rate constant, glucose metabolic rate) have no prognostic value in these patients.