We aimed to evaluate the prognostic value of early response assessment using a volumetric fluorine-18-fluorodeoxyglucose (18F-FDG) PET analysis in chemotherapy-treated patients with non-small-cell lung cancer (NSCLC).Materials and methods
We retrospectively reviewed 33 patients with NSCLC who received first-line chemotherapy and performed 18F-FDG PET/computed tomography before (baseline PET) and after two cycles of chemotherapy (interim PET). The maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) of the total malignant lesion were measured in baseline (SUV1 and MTV1) and interim (SUV2 and MTV2) PET images, and percentage changes in SUVmax (ΔSUV) and MTV (ΔMTV) were calculated between the two images. We compared PET parameters and clinicopathologic variables in terms of the 2-year overall survival (OS).Results
The median follow-up period was 14.3 months and the 2-year OS was 31%. In PET images, the mean SUV1, MTV1, SUV2, MTV2, ΔSUV, and ΔMTV were 13.1±4.5, 307.9±340.0 cm3, 9.5±5.1, 180.4±29.6 cm3, 27±28%, and 42±65%, respectively. In univariable analysis, M stage, TNM stage, and all six PET parameters associated significantly with OS. Both the MTV1 and the ΔMTV were tested against OS controlling for M stage, one at time, and the effect remained significant in multivariable analyses.Conclusion
A smaller baseline MTV and greater decrease in MTV between baseline and interim PET images are associated with a significantly prolonged OS. A volume-based 18F-FDG PET analysis would facilitate prediction of clinical outcome and identification of treatment-resistant patients early during chemotherapy and could thus be used in personalized treatment approaches for patients with NSCLC.