Positive imaging of thymoma by 11C-acetate positron emission tomography

Several studies have shown that fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) is not useful for the diagnosis of thymoma. We describe 3 patients with thymoma who underwent both FDG-PET and carbon-11 (11C) acetate (AC)-PET. Although all three thymomas were successfully imaged by AC-PET, one of the thymomas was not imaged by FDG-PET. These results suggest that AC-PET may have a potentially important role in the diagnosis of thymoma. This is the first report of the use of AC-PET for diagnostic imaging of thymoma.