%0 Journal Article %A Zhongling Qiu %A Chentian Shen %A Weijun Wei %A Hongjun Song %A Quanyong Luo %T Clinical management and outcomes in differentiated thyroid cancer patients with positive postoperative-stimulated thyroglobulin antibody and undetectable postoperative-stimulated thyroglobulin at initial 131I ablation after total thyroidectomy %D 2016 %J Journal of Nuclear Medicine %P 2711a-2711a %V 57 %N supplement 2 %X 2711aObjectives Positive serum antithyroglobulin antibody (TgAb) can be used as a surrogate marker of persistent or recurrent disease (PRD), which remains controversial in differentiated thyroid cancer (DTC) patients. We prospectively assessed the outcomes of DTC patients presenting with positive postoperative-stimulated serum (ps)-TgAb and lower ps-Tg (<1 ng/mL) at initial 131I ablation after total thyroidectomy.Methods A total of 414 DTC patients treated with 131I after total thyroidectomy between January 2005 and January 2012 were analyzed. We recorded all serum TgAb levels to evaluate their disease status at initial 131I ablation and during the follow-up period. Ps-TgAb 蠅40 KIU/L was defined as TgAb positive. PRD of DTC was assessed by 131I-WBS, 18F-FDG PET/CT, CT, neck ultrasonography, cytological study, or surgical pathology.Results Of the 414 patients enrolled, serum TgAb gradually decreased in 337 (81.40%) patients and increased in 77 (18.60 %) patients. Patients who underwent total thyroidectomy without lymph node dissection, in whom pathology did not show lymphocytic thyroiditis, with T stage (T4), the risk classification and presence of PRD of DTC had statistically significant impacts on changes in serum TgAb level (all P <0.05). Among them, 291 (70.29%) were free of disease, and 123 (29.71%) had PRD of DTC. Total thyroidectomy without lymph node dissection, absence of lymphocytic thyroiditis by pathology, risk classification, ps-TgAb level and dynamic serum TgAb changes had statistically significant impacts on PRD in theses DTC patients (all P < 0.05). The optimal cut-off value of serum TgAb for predicting PRD of DTC was 365.50 (AUC 0.728, 95% CI 0.675-0.781; sensitivity = 69.9%; specificity= 69.5%).Conclusions The majority of DTC patients with ps-TgAb and lower ps-Tg (<1 ng/mL) at initial 131I ablation showed gradually decreased serum TgAb which indicates more favorable outcomes for these patients in the course of follow-up. A Ps-TgAb level >365.50 KIU/L demonstrates a high positive PRD rate in these DTC patients. Total thyroidectomy without lymph node dissection, pathology showing no lymphocytic thyroiditis, an intermediate-high risk classification, ps-TgAb level and increasing dynamic serum TgAb may be closely associated with PRD of these DTC patients. %U