The correlation study between the glucose metabolism of 18F-FDG PET/CT incidental thyroid cancer and clinicopathologic characteristics / 中国癌症杂志

ABSTRACT

Background and purpose:The proportion of incidental thyroid cancer in PET imaging was sig-niifcantly increased with the wide application of18F-FDG PET/CT. The correlation between the glucose metabolism of thyroid incidental thyroid cancer and pathological changes is unclear. The objective of this study is to analyze the relationship between the glucose metabolism by18F-FDG PET/CT and tumor differentiation or lymph node metastasis in patients with incidental thyroid cancer.Methods:A total of 195 patients with focal FDG-avid thyroid incidentaloma during cancer evaluation were enrolled. Fifty-three patients were diagnosed as having thyroid cancer by the pathology. The SUVmax of thyroid cancer foci, lesion size, lesion number, and SUVmax of normal thyroid tissue were quantiifed. The tumor pathological grades and lymph node metastasis were analyzed by the pathology. The patients were broken down into 4 groups (G1, G2, G3 and G4) according to the tumor pathological grades and lymph node metastasis (differentiated thyroid cancer, non-differentiated thyroid cancer, without lymph node metastasis and with lymph node metastasis). The differences of glucose metabolism between G1and G2groups, G3 and G4 groups were analyzed.Results:Fifty-three foci were found by PET imaging. Sixty-two foci were found by the pathology (37 papillary thyroid carcinoma, 4 follicular thyroid carcinoma, 9 medullary thyroid carcinoma, 3 poorly differentiated thyroid cancer). The SUVmax in the normal thyroid tissue, G1and G2were 1.51±0.30, 4.25±1.70 and 6.34±2.45, respectively. The SUVmax in the G1and G2were signiifcantly higher than in the normal thyroid tissue (t=11.0,t=7.10,P0.05;t=0.33,P=0.56).Conclusion:The differentiated incidental thyroid carcinoma and non-differentiated incidental thyroid carcinoma had high glucose metabolism, and there was no signiifcant difference in the levels of glucose metabolism in different differentiation degree and metastasis ability cancer.