Impact on Radiological and Pathological Response with Neoadjuvant Chemoradiation and Its Effect on Survival in Squamous Cell Carcinoma of Thoracic Esophagus.

Abstract

Neoadjuvant chemoradiation (NCRT) has been shown to improve survival in patients with locally advanced esophageal squamous cell carcinoma (SCC). The aim of the present study was to evaluate the role of 18-FDG PET-CT in predicting pathological response to NCRT. We assessed 70 patients of esophageal SCC who underwent NCRT and were evaluated with baseline and post chemoradiation 18F-FDG PET-CT scan. Receiver operating characteristic (ROC) curve was generated by analyzing the sensitivity and specificity of different cut-off points for defining a positive test and their ability to predict pathological complete response. Univariate and multivariate analysis were performed using log-rank and Cox proportional hazards models, and survival curves were estimated using the Kaplan-Meier method. Radiological and pathological complete response was achieved in 44.3% (n=31) and 34.3% (n=24) patients, respectively. Using ROC curves, post-treatment standardized uptake value (SUV) max [3.25, area under curve (AUC) 0.752] and % change in SUVmax cut-off value (72.32%, AUC 0.705) was used to predict pathological response. Significant associations between pathological response in primary tumor and post chemotherapy/radiotherapy SUVmax values (p=0.016), % change in SUVmax (p=0.006), radiological response in primary (p=0.006), and grade of dysphagia at presentation (p=0.041) were observed. Mean overall survival and relapse free survival was 83 and 58%, respectively at 34months. 18F-FDG PET-CT can be used to predict pathological response to NCRT in locally advanced SCC.