The prognostic effect of pretreatment 18F-FDG PET/CT metabolic parameters in locally advanced Esophageal Squamous Cell Carcinoma treated with definitive chemoradiotherapy.

INTRODUCTION

In this study, we aimed to examine the relation between pre-treatment 18F-FDG PET/CT metabolic parameters [(including the maximum standard uptake value (SUV), metabolic tumor volume (MTV), and tumor lesion glycolysis (TLG)] and treatment response and survival in locally-advanced Esophageal Squamous Cell Cancer (ESCC) treated with definitive chemoradiotherapy (dCRT).

METHODS

A total 76 patients with locally-advanced ESCC who received dCRT between June 2015 and December 2019 were included in this retrospective study. Patients were divided into two groups as complete response (CR) or non-complete response (Non-CR) according to response to treatment. AUC was obtained as 0.749 (p < 0.001) in the ROC curve drawn by MTV for the CR. The MTV value was ≤12 cm, with 72.1% sensitivity and 73.0% specificity.

RESULTS

Of the 76 patients, 38 (50%) were male and 38 (50%) were female. The median age was 62 (39-84) years. The treatment response in 35 (46%) patients was CR. MTV value was >12cm3 in 41(54%) patients. Median follow-up time was 14.5 months. In patients with MTV>12cm3, median progression-free survival(mPFS) and median overall survival(mOS) were 9 months and 11 months, respectively, whereas mPFS and OS could not be reached in those with MTV≤12 cm3 (p < 0.001 and p < 0.001, respectively). In patients with non-CR, mPFS and mOS were 8 months and 9 months, respectively, whereas mPFS and OS could not be reached in patients with CR (p < 0.001 and p < 0.001, respectively). In multivariate analysis, age (odds ratio [OR], 1.07), ECOG PS (OR, 11.1), and MTV (OR, 4.73) were found to be the factors affecting treatment response.

CONCLUSION

In our study, treatment response and MTV were found to be the factors associated with survival in patients treated with dCRT, showing the pre-treatment MTV value as a predictor of treatment response.