Identification of (18)F-FDG PET/CT Parameters Associated with Weight Loss in Patients with Esophageal Cancer

(18)F-FDG PET-CT is routinely performed as part of the initial staging of numerous cancers. Other than having descriptive, predictive and prognostic values for tumors, (18)F-FDG PET-CT provides full-body data, which could inform on concurrent pathophysiological processes such as malnutrition. To test this hypothesis, we measured the (18)F-FDG uptake in several organs and evaluated their association with weight loss in patients at diagnosis of esophageal cancer. Forty-eight patients were included in this retrospective monocentric study. (18)F-FDG uptake quantification was performed in the brain, the liver, the spleen, bone marrow, muscle and the esophageal tumor itself and was compared between patients with different amounts of weight loss. We found that Total Lesion Glycolysis (TLG) and peak Standardized Uptake Values (SUV(peak)) measured in the brain correlated with the amount of weight loss: TLG was, on average, higher in patients who had lost more than 5% of their usual weight, whereas brain SUV(peak) were, on average, lower in patients who had lost more than 10% of their weight. Higher TLG and lower brain SUV(peak) were associated with worse OS in the univariate analysis. This study reports a new and significant association between (18)F-FDG uptake in the brain and initial weight loss in patients with esophageal cancer.