The usefulness of fluorodeoxyglucose-positron emission tomography as a preoperative diagnostic tool for thymic epithelial tumors

BACKGROUND: To investigate the usefulness of (18)F-fluorodeoxy glucose-positron emission tomography ((18)F-FDG PET) for the preoperative imaging diagnosis of malignant grade in thymic epithelial tumors (TETs) and the correlation between the maximum standardized uptake value (SUVmax) and tumor size in TETs. METHODS: We retrospectively investigated 51 patients with TETs performed (18)F-FDG PET. The SUVmax was compared between thymic carcinomas and thymomas. We also evaluated the difference in the SUVmax limited to small TETs. In addition, the correlation between the SUVmax and the tumor size was evaluated. RESULTS: The mean SUVmax of thymic carcinomas (n=12) and thymomas (n=39) was 5.71±2.6 and 3.08±1.4, respectively. The SUVmax of thymic carcinomas was significantly higher than that of thymomas (P