TY - JOUR T1 - <strong>Abnormal brain glucose metabolism and mood disorders in thyroid cancer patients after twenty-one day withdrawal of levothyroxine</strong> JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1498 LP - 1498 VL - 60 IS - supplement 1 AU - Shuqi Wu Y1 - 2019/05/01 UR - http://jnm.snmjournals.org/content/60/supplement_1/1498.abstract N2 - 1498Background: In our department, the method of 21 days withdrawal of levothyroxine is commonly used in differentiated thyroid cancer (DTC) patients after total thyroidectomy, preparing for 131I ablation. Aim of this study was to characterize brain metabolic abnormalities in them, using 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT). Methods: We recruited a total of thirty-eight DTC patients (12 men, 26 women; age range, 25-69 years; mean age, 45.8 years) and thirty-four healthy subjects (7 men, 27 women; age range, 27-82 years; mean age, 48.97 years) for this cross-sectional study, followed 1:1 paring rules, age- and sex-matched. Twenty-three of patients were hypothyroidism with 21 days levothyroxine withdrawal. The other fifteen DTC patients replaced by levothyroxine and the healthy subjects were euthyroidism. All the subjects underwent brain 18F-FDG PET/CT scans. Two samples t-test and multivariate regression was applied for the image data analyzing the regional cerebral glucose metabolism (rCMglu), adjusted for age and gender by statistical parametric mapping (SPM5). Patients were asked to complete Hamilton Depression Rating Scale (17 items, HRDS-17) and Hamilton Anxiety Rating Scale (HAMA) questionnaires for assessing mood disorders by a trained doctor.Results: The rCMglu demonstrated lower 18F-FDG uptake mainly in the bilateral occipital lobe including the right cuneus (BA17/18), the right middle occipital gyrus(BA19), the left lingual gyrus(BA18) and left inferior occipital gyrus(BA18) in withdrawal group than in replacement group (sum, 1351 voxels; uncorrected p&lt;0.005). Positive loadings were mainly observed in the left frontal lobe including the left orbital gyrus, inferior frontal gyrus (BA47), and left claustrum (sum, 265 voxels; uncorrected p&lt;0.005). When comparing with healthy subjects, the bilateral occipital lobes, the left parietal and frontal lobe were observed lower rCMglu including the bilateral cuneus (BA18/19), middle occipital gyrus (BA19), left inferior/superior parietal gyrus (BA40/7), left precuneus (BA7), left sub-gyral (BA40), left middle frontal gyrus(BA10) and right superior occipital gyrus(BA19) (sum, 2869 voxels; uncorrected p&lt;0.005). The left inferior parietal lobe exhibited the most significant extent of the involved area (sum, 1210 voxels; uncorrected p&lt;0.005). Right limbic lobe and sub-lobar including the hippocampus (R) and pulvinar (R) showed increased rCMglu (sum, 300 voxels; uncorrected p&lt;0.005). The score of HRDS-17 and HAMA were both higher in withdrawal group than in replacement group in DTC patients (14.7±5.8 vs 3.8±5.5, t=-5.74, p=0.00; 9.3±4.3 vs 2.7±4.1, t=-4.74, p=0.00, respectively). Conclusion: This study identified that even for the short time (21 days) of levothyroxine withdrawal may induce impairment in brain glucose metabolism for DTC patients. And there are more depressive and anxious patients were found in the withdrawal group. ER -