Abstract:

Objective  To explore the role of thyroid ultrasound combined with serum thyroglobulin(Tg) and anti-thyroglobulin antibody(TgAb) in the diagnosis of postoperative recurrence or metastasis of thyroid cancer(TC).

Methods  In total, 192 patients with differentiated thyroid carcinoma(DTC) who needed to be retreated with 131I clearanceafter treatment with surgical resection and 131I clearance in our hospital were selected as the research subjects. Thyroid ultrasonography was performed and serumTg and TgAb levels were detected. 131I whole-body single photon emission computed tomography(SPECT) imaging was performed at 1 week after retreatment with 131I clearance. The results of ultrasound and Tg levels compared with whole body scan(WBS) were recorded. The effects of TgAb levels and Tg on the diagnosis of recurrence or metastasis after DTC were analyzed, and binary Logistic regression analysis was used to analyze the correlation of ultrasound and positive Tg with WBS results.

Results  The accuracy, specificity and sensitivity of ultrasound, Tg and the combination of the two in the diagnosis of recurrence or metastasis after DTC were 75.00%, 58.33%, 78.85%; 75.00%, 66.67%, 76.92%; 92.11%, 71.43%, 96.77 %, respectively. When TgAb≥100 U/mL and ＜100 U/mL, the diagnostic efficiency of Tg for recurrence or metastasis after DTC was 52.17%, 50.00%, 52.38% and 87.80%, 70.00%, 93.55%, respectively.Binary Logistic regression analysis showed that the risk of positive WBS in ultrasound and Tg-positive patients was 5.218 and 6.667 times that of negative patients.

Conclusion  Thyroid ultrasound combined with serum Tg and TgAb detection can effectively improve the diagnosis efficiency of recurrence or metastasis after DTC. Comprehensive multiple indicators can be used for judgement, and 131I-WBS examination should be performed, when necessary, to reduce the rate of missed diagnosis.

Key words: thyroid neoplasms, thyroglobulin, recurrence and metastasis