Predictive value of stimulated thyroglobulin before the first 131I ablation for metastasis of differentiated thyroid carcinoma in children and adolescents

Objective To investigate the clinical value of pre-ablation stimulated thyroglobulin (psTg) in the prediction of metastasis of differentiated thyroid carcinoma (DTC) in children and adolescents. Methods The study included 51 children and adolescent patients (20 males, 31 females, age: 8-18(13.5±3.0) years) with DTC who had undergone total thyroidectomy and lymphadenectomy and were going to have the first 131I ablation therapy from March 2012 to December 2017 in the Affiliated Cancer Hospital of Zhengzhou University. Patients′ serum thyroglobulin antibody (TgAb) levels were normal. They were divided into M0 group (without metastasis) and M1 group (with metastasis). The psTg difference between the two groups was compared using Mann-Whitney U test. The receiver operating characteristic (ROC) curves and diagnostic critical point (DCP) of psTg for the metastasis prediction were analyzed. Results The psTg levels of M0 group (n=20) and M1 group (n=31) were 5.76(3.38, 18.51) μg/L and 280.46(37.66, 470.00) μg/L, respectively, and the difference between the two groups was statistically significant (U=41, P<0.05). The area under the ROC curve of psTg was 0.934 (95% CI: 0.869-0.999) with the sensitivity, specificity and accuracy of 80.6%(25/31), 100%(20/20) and 88.2%(45/51) respectively, with the DCP value of 31.98 μg/L. Conclusion The psTg value detected before the first 131I treatment has an important predictive value for postoperative metastasis of DTC in children and adolescents. Key words: Thyroid neoplasms; Neoplasm metastasis; Thyroglobulin; Radiotherapy; Iodine radioisotopes; Child; Adolescent