Combining Thyroglobulin Levels in Lymph Node Wash-out Fluid with TI-RADS to Predict Lymph Node Metastasis in Papillary Thyroid Carcinoma

Abstract

Objective
This study was aimed at investigating if the lymph node aspirated wash-out liquid thyroglobulin level and thyroid imaging reporting and data system (TI-RADS) nodule score can be the predictive factor for cervical lymph node metastasis in patients with papillary thyroid carcinoma (PTC).
Methods
The study included 251 patients with surgically confirmed PTC. All the patients underwent preoperative thyroid and cervical ultrasound examination using ACR TI-RADS classification, fine-needle aspiration biopsy (FNAB) for BRAF V600E gene detection, and thyroglobulin (Tg) detection in lymph node aspiration fluid. The results of these examinations and tests were statistically analyzed. A binary logistic regression model was used to determine the predictive impact of Tg levels, gene mutation status, and TI-RADS nodule score on lymph node metastasis.
Results
Among the enrolled patients, 219/251 (87.25%), had BRAF V600E gene mutations and 132/251 (52.59%) had cervical lymph node metastasis. The Tg level in the lymph node aspiration fluid of patients with metastasis was significantly higher than in those without metastasis (324.94 ± 192.52 ng/mL vs 67.93 ± 136.62 ng/mL, P = 0.000), but there was no significant difference in serum Tg levels between the two groups (27.08 ± 71.60 ng/mL vs 20.73 ± 55.21 ng/mL, P = 0.276). The area under the ROC curve (AUC) for lymph node aspiration fluid Tg was 0.858. Thyroglobulin level has a significant positive effect on lymph node metastasis, with a regression coefficient of 0.003 and P = 0.000 < 0.001. BARF V600E mutation status and TI-RADS nodule score do not have a significant effect on lymph node metastasis, with P-values greater than 0.05.
Conclusion
Thyroglobulin levels of lymph node aspiration fluid has a good predictive value for the diagnosis of cervical lymph node metastasis in PTC patients with larger nodules.