Diagnostic value of shear wave elastography and FNA-Tg in cervical lymph node metastasis of thyroid papillary carcinoma

Abstract:

Objective To investigate shear wave elastography（SWE）and fine-needle aspiration washout thyroglobulin（FNA-Tg）in the diagnosis of cervical lymph node metastasis of thyroid papillary carcinoma.Methods The data of 159 patients with papillary thyroid carcinoma（PTC） confirmed by pathology were analyzed retrospectively，and 211 suspected lymph nodes in the neck were examined by ultrasonic examination，SWE E_mean and FNA-Tg. The diagnostic efficacy of each method was compared with the postoperative pathological results as the gold standard.Results ①The SWE E_mean metastasis group [（50.96±27.66） kPa] was significantly higher than the non-metastasis group [（32.20±17.34） kPa]，with a statistically significant difference（t=8.761，P<0.01）. The receiver operating characteristic（ROC） curve analysis showed that SWE E_mean optimal diagnostic threshold of 40.42 kPa had a higher predictive value for cervical lymph node metastasis of PTC，with an area under the curve（AUC） of 0.849（95%CI=0.795-0.902，P<0.01）. ②Compared with SWE E_mean，the sensitivity，specificity，diagnostic value，positive predictive value and negative predictive value were significantly increased（χ²=7.724，28.230，35.094，21.731，9.890；P=0.005，<0.000，<0.000，<0.000，0.002）. Compared with FNA-Tg，the sensitivity，specificity，diagnostic value，positive predictive value and negative predictive value of the combined method were significantly increased（χ²=7.724，6.014，13.526，6.137，7.602；P=0.005，0.014，<0.000，0.013，0.006）. ③The accuracy of SWE E_mean was 53.8% with and 79.8% without cystic changes in lymph nodes，respectively，with a statistical significance（χ²=4.819，P=0.028）. The accuracy of FNA-Tg was 92.3% and 87.4%，respectively，with no significant difference（χ²=0.275，P=0.600）.Conclusion FNA-Tg has a high accuracy in the diagnosis of PTC metastatic lymph nodes，and is not affected by the presence or absence of cystic changes in lymph nodes. The combination of SWE E_mean and FNA-Tg can significantly improve the diagnostic efficiency.