Predictive value of stimulated thyroglobulin for metastases from differentiated thyroid carcinoma be-fore the first 131Ⅰtreatment / 中华核医学与分子影像杂志

ABSTRACT

Objective To explore the relationship between the stimulated thyroglobulin ( sTg) and site, number and diameter of metastatic lesions in patients with differentiated thyroid carcinoma (DTC) before the first 131 I treatment, and to evaluate the predictive value of sTg for different metastatic sites. Methods A total of 567 DTC patients (179 males, 388 females; age (45.3±12.3) years) who received the first 131Ⅰ treatment between January 2012 and June 2017 were included. Thyroglobulin antibody (TgAb), sTg and thyroid stimulating hormone ( TSH) were determined within 1 week before 131 I treatment. Metastases were detected by ultrasonography, CT or 18 F-fluorodeoxyglucose ( FDG ) PET/CT, 131 I whole-body scan, SPECT/CT imaging and pathology. sTg levels of patients with different metastatic sites and different metasta-sis numbers or lesion diameters were compared ( Kruskal-Wallis H test) . Spearman correlation analysis was performed on the number, diameter and sTg level of metastases. The receiver operating characteristic ( ROC) curve was used to explore the predictive value of sTg before the first 131 I treatment for DTC metasta-sis. Results The median values of sTg in the bone, lung, lymph node metastases groups and non-metasta-sis group were 500.00, 104.40, 27.45, 2.39μg/L, respectively, and there were significant differences, ex-cept for bone and lung metastases groups ( H range -294.605 to 175.162, all P<0.05) . The sTg levels of lung metastasis group and lymph node metastasis group were both decreased by the order of metastasis num- bers (≥3, =2, =1;H range-57.887 to 48.763, all P<0.05) . As to the diameter of metastases, the sTg levels of >2.0 cm, 1.1-2.0 cm, and≤1.0 cm subgroups in the lung metastasis group and lymph node me-tastasis group were also decreased in order ( H range -69.935 to 61.043, all P<0.05) . Spearman correla-tion analysis showed that the number ( rs=0.568, 0.606) and diameter ( rs=0.806, 0.664) of the metasta-ses in the lung and lymph node metastases group were positively correlated with sTg (all P<0.05). Areas under ROC curves for sTg to predict bone, lung and lymph node metastasis were 0.935, 0.843 and 0.791 re-spectively. The threshold values were 197. 65, 23. 21 and 10. 96 μg/L respectively. The sensitivities and the specificities were 91.70％, 79.60％, 67.20％ and 97.20％, 80.80％, 82.70％ respectively. Conclusions Tg level before the first 131 I treatment has a certain predictive value for the metastasis, metastatic site and num-ber or diameter in DTC patients.