Functional visceral fat activity evaluated by preoperative F-18 FDG PET/CT predicts regional lymph node metastasis in differentiated thyroid cancer

Abstract

ObjectiveWe investigated the predictive role of functional visceral fat activity evaluated by preoperative F-18 FDG PET/CT for regional lymph node metastasis in patients with differentiated thyroid cancer. Design and patientsFifty-eight patients with newly diagnosed differentiated thyroid cancer were enrolled in this study, retrospectively (men 14; women 44; age 5314.5). They all received preoperative F-18 FDG PET/CT and surgery. Functional visceral fat activity was defined as maximum standardized uptake value (SUVmax) of visceral fat divided by SUVmax of subcutaneous fat (V/S ratio). Pathology results were confirmed through the surgical specimens. ResultsThe patients with regional lymph node metastasis showed higher functional visceral fat activity (V/S ratio) than the patients without regional lymph node metastasis (2.12 +/- 0.6 vs 1.62 +/- 0.34, P=.001). V/S ratio of 1.78 was suggested as an optimal cut-off value for predicting regional lymph node metastasis (sensitivity; 70.3%, specificity; 83.3%, area under the curve; 0.778, P<.0001). Furthermore, functional visceral fat activity was significantly associated with regional lymph node metastasis in patients with differentiated thyroid cancer by univariate and multivariate analyses. ConclusionsFunctional visceral fat activity significantly affects the regional lymph node metastasis status in patients with differentiated thyroid cancer. Furthermore, it may also be useful to predict regional lymph node metastasis.