[Analysis of glucose metabolism in patients with esophageal cancer by PET: estimation of hexokinase activity in the tumor and usefulness for clinical assessment using 18F-fluorodeoxyglucose].

We evaluated glucose metabolism of esophageal cancer by PET using 18F-fluorodeoxyglucose (FDG), in order to investigate its clinical usefulness. In 11 advanced cases k3 value reflecting hexokinase activity and Ci/Cp ratio expressing FDG uptake were calculated from radioactivity in the tumor (Ci) and the plasma (Cp). Both k3 and Ci/Cp were well correlated with hexokinase activity from the resected specimen, so Ci/Cp was considered to be a convenient index for clinical assessment of esophageal cancer. Forty-two cases before treatment revealed high accumulation of FDG, and 41 showed more than 2.0 of Ci/Cp. But, 10 normal controls and one esophageal benign tumor showed less than 2.0. As for 13 post-operative cases, 6 cases out of 7 with recurrence showed more than 2.0 for Ci/Cp, but all 6 cases of non-recurrent cases showed less than 2.0. FDG PET is an useful tool for differential diagnosis of recurrence. The clinicopathological findings were investigated in 26 resected cases. Age, location, vertical extension, histologic feature, lymph node metastasis and histologic stage were not correlative with Ci/Cp. As for DNA ploidy pattern, aneuploidy group showed significantly high Ci/Cp rather than diploidy group. Eight cases which showed more than 5.0 of Ci/Cp resulted in poor prognoses compared with 14 cases which showed less than 5.0.