Purpose: The aim of this study was to investigate whether standard uptake values (SUVs) of pretreatment 18F-FDG PET/CT were the surrogate parameters for predicting the outcomes in locally advanced esophageal squamous cell carcinoma patients treated with definitive chemoradiotherapy.
Materials and methods: Sixty patients with esophageal squamous cell carcinoma underwent pretreatment 18F-FDG PET/CT and received definitive chemoradiotherapy. 18F-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.
Results: 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, p = 0.02) and PFS (HR = 6.53, p < 0.001).
Conclusions: Our study suggests that SUVmean of the primary tumor in pretreatment 18F-FDG PET/CT may be used as an independent predictor in esophageal squamous cell carcinoma patients treated with definitive chemoradiotherapy.
Keywords: 18F-FDG PET/CT; Definitive chemoradiotherapy; Esophageal squamous cell carcinoma; Prognosis; SUVmean; Standard uptake value.
© The Author(s), under exclusive licence to Korean Society of Nuclear Medicine 2022.