Early Assessment of Metabolic Response by 18F-FDG PET During Concomitant Radiochemotherapy of Non-Small Cell Lung Carcinoma Is Associated With Survival A Retrospective Single-Center Study

Background and Purpose: We performed a retrospective single-center study to assess if midtreatment F-18-FDG PET/CT could predict local control and survival in patients with locally advanced non-small cell lung cancer treated with concurrent chemoradiotherapy. Methods: Thirty-one consecutive patients with unresectable or locally advanced lung cancer (T2-4 N0-3 M0) were treated with concurrent chemoradiotherapy in our center. Each patient received F-18-FDG PET/CT before treatment and at midtreatment time when a radiation therapy dose of 30 Gy was delivered. We assessed several PET/CT parameters as follows: SUVmax, Delta SUVmean, Delta SUVmax, variation of hypermetabolic tumor volume, and the variation of tumor total lesion glycolysis (Delta TLG). Univariate analysis was performed, and a stepwise procedure was used to define final multivariate model. Results: The Delta TLG was statistically correlated to overall survival (OS) (P = 0.035), progression-free survival (P = 0.023), and local control (P = 0.043) in univariate analysis. A decrease in TLG over 15% was statistically correlated to a better OS (P = 0.007; hazards ratio [HR], 7.439; 95% confidence interval [CI], 1.168-28.897) and progression-free survival (P = 0.010; HR, 5.695; 95% CI, 1.506-21.537) in univariate analysis. In multivariate analysis,.TLG superior to -15% was significantly correlated to aworse OS (P = 0.020; HR, 5.973; 95% CI, 1.324-26.953). Conclusions: Early assessment of TLG response by 18F-FDG PET/CT during concomitant radiochemotherapy of non-small cell lung cancer might be associated with survival.