摘要Background:Postoperative preablative stimulated thyroglobulin (ps-Tg) has been evaluated in predicting prognosis and success of ablation regarding differentiated thyroid cancer (DTC);however,its relationship with recurrence risk and radioiodine decision-making remains uncertain,especially in Chinese DTC patients.We aimed to evaluate the association between ps-Tg and recurrence risk stratification in DTC,to provide incremental values for ps-Tg in postoperative assessment and radioiodine management.Methods:Seven hundred and seven patients with DTC were included;low-risk (L;n =90),intermediate-risk (I;n =283),and high-risk (H;n =334,117 with distant metastasis [M 1]) patients were divided according to recurrence risk stratification.The M 1 group was further analyzed regarding evidence of metastasis.Cut-off values of ps-Tg were obtained using receiver operating characteristic analysis.Results:Patients with more advanced disease at initial risk stratification were more likely to have higher ps-Tg levels (Ⅰ vs.L:P ＜ 0.05;H vs.I:P ＜ 0.001;H vs.L:P ＜ 0.001).The corresponding cut-off value of ps-Tg for distinguishing sensitivity and specificity in each of the two groups was 2.95 ng/ml (Ⅰ vs.L:61.5％,63.3％),29.5 ng/ml (H vs.I:41.9％,92.6％),47.1 ng/ml (M1 vs.M0 in the H group:79.5％,88.9％) and 47.1 ng/ml (M1 vs.M0 in all patients:79.5％,93.7％).With the cut-off value at 47.1 ng/ml,ps-Tg was the only factor that could be used to identify distant metastases,and consequently if measured before radioiodine therapy would prevent 10.26％of patients with M 1 from undertreatment.Conclusions:Ps-Tg,as an ongoing reassessment marker,favors differential recurrence risk grading and provides incremental values for radioiodine treatment decision-making.