Relationship between changes of serum Tg, TgAb and the detection of differentiated thyroid carcinoma after iodine-131 treatment

Objective: To investigate the relationship between changes of Tg, TgAb and the detection of differentiated thyroid carcinoma (DTC) by iodine-131 whole body scan (Dx-WBS) in the patients after thyroid ablation, and provide clinical evidence for judging recurrence and metastasis of DTC. Methods: A total of 83 patients with DTC were collected retrospectively 6 months or more after ¹³¹I ablation therapy posttotal thyroidectomy or near-total thyroidectomy. Serum Tg and TgAb levels were measured, the thyroid function was checked and Dx-WBS was performed. Results: The changes of TgAb were affected by Tg levels. When we combined Tg and Dx-WBS, The diagnosis accuracy rate for DTC recurrence and metastasis was as high as 95%. Conclusion: Tg testing has the highest accuracy in screening on DTC patients after 6 months or more Iodine 131 treatment. But there might besome false negatives because of TgAb interference. Dx-WBS parallel testing is highly recommended in conjunction with Tg for the diagnosis in metastasis and recurrence of DTC. (authors)