Clinical value of TSH-stimulated thyroglobulin in evaluation of metastasis from differentiated thyroid carcinoma after 131I treatment / 中华核医学与分子影像杂志

ABSTRACT

Objective To investigate the critical value of TSH-stimulated Tg(sTg) in the diagnosis of metastasis from DTC, and to evaluate the diagnostic value of the ratio of sTg to suppressed Tg (sTg/suppressed Tg).Methods A total of 330 post-operative DTC patients(87 males, 243 females, age range 12-70 years)who underwent thyroid remnant ablation from August 2008 to December 2014 were retrospectively reviewed.Their serum TgAb levels were normal.The patients were divided into non-metastasis group(147 cases)and metastasis group(183 cases) according to results of ultrasonography, CT and WBS.The difference of sTg between the two groups were compared by Mann-Whitney rank sum test.ROC curve was used to analyze the relationship between sTg, sTg/suppressed Tg ratio and metastasis, the cutoff value was calculated.Results The sTg was significantly different between the non-metastasis group and metastasis group 1.0 (0.1, 2.0) μg/L vs 36.5 (3.9, 126.7) μg/L;u=-6.642, P<0.05.The AUC for ROC curve in metastasis group was 0.85, and the cutoff value was 2.05 μg/L, with the sensitivity 85.2%, specificity 67.3%, and accuracy 82.3%.While sTg<2.05 μg/L, the AUC of sTg/suppressed Tg ratio was 0.941, and the cutoff value was 4.3, with the sensitivity 93.3%, specificity 88.2%, and accuracy 92.3%.Conclusions The sTg has a specific value for the diagnosis of metastasis from DTC after operation and the cutoff value is 2.05 μg/L in this set of patients.The ratio of sTg/suppressed Tg could be used to correct the sTg and to improve the diagnostic sensitivity.