Pretreatment 18 F-FDG PET/CT-Derived Parameters in Predicting Clinical Outcomes of Locally Advanced Upper Third Esophageal Squamous Cell Carcinoma After Definitive Chemoradiation Therapy

The aim of this study was to investigate whether standard uptake values (SUVs) of pretreatment F-FDG PET/CT were the surrogate parameters for predicting the outcomes in locally advanced esophageal squamous cell carcinoma patients treated with definitive chemoradiotherapy. Sixty patients with esophageal squamous cell carcinoma underwent pretreatment F-FDG PET/CT and received definitive chemoradiotherapy. F-FDG metabolic parameters including SUVmax, SUVmean, SULpeak, total lesion glycolysis (TLG), and metabolic tumor volume (MTV) of primary tumor were calculated. The receiver-operating characteristic (ROC) curve was used to determine the optimal cutoff value of FDG PET/CT-derived parameters that associated with treatment response. Estimating progression-free survival (PFS) and overall survival (OS) was analyzed by using Kaplan-Meier methods. Univariate and multivariate analysis for PFS and OS was performed using Cox regression. Complete response was achieved in 38.3%. The 4-year OS and PFS rates were 48.6% and 44.4%, respectively. SUVmean with a cutoff value of 6.1 could predict complete response with sensitivity of 69.6%, specificity of 78.4%, and accuracy of 75%. Cox multi-factor regression analyses revealed SUVmean > 6.1 as an independent prognostic factor for OS (HR = 6.74, = 0.02) and PFS (HR = 6.53, < 0.001). Our study suggests that SUVmean of the primary tumor in pretreatment F-FDG PET/CT may be used as an independent predictor in esophageal squamous cell carcinoma patients treated with definitive chemoradiotherapy.