An Absolute Standardized Uptake Value Is More Useful than the Decreased Rate of Uptake of FDG-PET to Predict Responses to Neoadjuvant Chemoradiotherapy for Esophageal Cancer

Background: Neoadjuvant chemoradiotherapy (CRT) is frequently performed for esophageal squamous cell carcinoma. In this study, we retrospectively assessed the standardized uptake value (SUV) of FDG-PET against decreased rates of SUV to assess the response of advanced esophageal squamous cell carcinoma patients to neoadjuvant CRT, and the correlation of this response with histopathological findings. Patients and Methods: Thirty-three patients receiving CRT followed by surgery were analyzed. Results: Using the decreased rate of maximum SUV, the sensitivity and specificity in distinguishing complete responders (CR) from non-CR patients was 63% and 44%. Using the maximum SUV before surgery, the sensitivity and specificity for distinguishing pathological CR from non-CR was 88% and 56%. Conclusions: To identify complete responders of CRT for esophageal cancer, absolute maximum SUV value is a better predictor than decreased rate of the maximum SUV.