Value of a 18F-FDG PET/CT Semi-quantitative Parameter (SUVmax) in Predicting the Survival of Patients with Esophageal Cancer Subtypes

Background: Flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan is employed for initial staging and restaging of esophageal cancer patients. Objectives: The present study aimed to assess the value of a semi-quantitative parameter of 18F-FDG PET/CT scan, that is, maximum standardized uptake value (SUVmax), to determine its correlation with patient survival in two subtypes of esophageal cancer, including squamous cell carcinoma (SCC) and adenocarcinoma. Patients and Methods: This cross-sectional study was performed on patients with esophageal SCC and adenocarcinoma, undergoing 18F-FDG PET/CT scan for initial staging before any treatment. The 18F-FDG PET/CT semi-quantitative parameter (SUVmax) was determined by reviewing the PET/CT images. The patients were reevaluated using 18F-FDG PET/CT scan for restaging within 12 - 24 months. Results: No significant difference was observed in the SUVmax values of the primary tumor, metastatic lymph nodes, or distant metastasis between the adenocarcinoma and SCC groups, regardless of response to treatment. Similarly, no significant association was found between the short-term survival of patients with adenocarcinoma and the SUVmax values of the primary tumor, metastatic lymph nodes, or distant metastasis. Based on the survival curve, one- and two-year survival rates were estimated at 75% and 63.9% in patients with SCC and at 80% and 60% in patients with adenocarcinoma, respectively. In the SCC group, a significantly higher SUVmax was detected in deceased patients with distant metastatic lesions compared to cancer survivors. According to the area under the ROC curve, the SUVmax of metastatic lesions showed high potential for predicting the mortality of SCC patients. Conclusion: The assessment of SUVmax in distant metastatic lesions by 18F-FDG-PET/CT may help predict the survival of patients with esophageal SCC. However, 18F-FDG-PET/CT findings were not associated with the survival of esophageal adenocarcinoma; therefore, further evaluations on a larger sample size and a longer follow-up are required.