Evaluation of Esophageal Cancers Using Fluorine-18-Fluorodeoxyglucose PET

To evaluate glucose metabolism in esophageal cancer, 48 patients were studied using PET with 18F-2-fluoro-2-deoxy-D-glucose (FDG). After transmission scans were obtained, 18F-FDG (148 MBq) was administered intravenously. In 11 patients, a dynamic study was performed to evaluate glucose metabolism. Using the changes of radioactivity in both plasma and tumor, rate constants (k1-k4) defined in the metabolic model for 18F-FDG were calculated. In 48 patients, static PET scans of the tumor (5-min scans) were obtained 60 min after administration. Fluorine-18-FDG activity within each tumor was corrected for physical decay and normalized by dose administration and patient weight to produce a standardized uptake value (SUV). Both the k3 value (n = 11) reflecting hexokinase activity and SUV (n = 13) were well correlated with hexokinase activity from the resected specimen (p < 0.05). Forty-seven of 48 patients before treatment revealed SUV greater than 2.0, but 10 normal control subjects and 1 esophageal benign tumor revealed less than 2.0 (accuracy rate 98.3%). Although clinicopathological findings did not correlate with SUV, except for two patients with carcinosarcoma, 23 patients with an SUV greater than 7.0 had a poor prognosis compared with 25 patients with SUVs less than 7.0. These findings suggest that 18F-FDG PET may be useful in distinguishing malignant tumors from benign lesions and in the preoperative evaluation of the prognostic factor.