The Value Of Joint Application Of Ultrasonic Imaging Guided Fine Needle Aspiration And Thyroglobulin Determination In Diagnosis Of Postoperative Lymph Node Metastasis Of Papillary Thyroid Cancer

Objective:To determine the diagnostic value of US-guided FNAC, Tg measurement inFNAwashout fluids (FNATg), and the combined FNAC and FNATg in postoperativecervical lymph nodes metastasis frompapillary thyroid carcinoma.Methods:One hundred and forty-eight cases of postoperative lymphadenopathy inpatients with papillary thyroid carcinoma were collectedfrom August2012toDecember2013. All patients underwent routine ultrasonography, US-guided FNAC,FNATg, Electro-chemiluminescence immunoassay (ECLIA), and Tg measurements.Two positive values of FNATg were selected for comparative analysis. All cases oflymphadenectasis were diagnosed by postsurgical pathology or bodkinbiopsy.Results:Ninety-four cases of the148nodes were malignant and53cases were benignlesions.1. FNAC detected64cases of metastatic lymph nodes,84cases ofnon-metastatic lymph nodes, and misdiagnosed30cases. The sensitivity, specificity,and accuracy of FNAC were68.1%,100.0%, and79.7%, respectively.2. Selecting a different cut-off value for determining positive. FNA-Tgchanged its sensitivity, specificity, and accuracy. A positive value of10.0ngl/LFNATg showed sensitivity, specificity, accuracy of98.9%,68.5%, and87.8%,respectively. Whenusing FNATg/serumTg>1as the positive value, the sensitivity,specificity, and accuracy were91.5%,88.9%, and90.5%, respectively. There was no obvious statistical significance in sensitivities, specificities, and accuracies. Theresults between the two groups had no obvious statistical significance（p>0.05）.Fifty-three cases of metastatic lymph nodes were diagnosed and verified byhistology when FNATg exceeded1000ng/ml.3. The sensitivities, specificities, accuracies of routine ultrasonography, FNAC,and using FNATg/serum Tg>1as the positive value were60.6%,90.7%, and71.6%;68.1%,100.0%, and79.7%; and91.5%,88.9%, and90.5%, respectively. FNATg isobviously more sensitive than FNAC and routine ultrasonography. The variance isstatistically meaningful (P<0.05).4.The sensitivities, specificities, and accuracies of FNAC and combined FNATgand FNAC were68.1%,100.0%, and79.7%;91.5%,88.9%, and90.5%, respectively.The two methods were considered statistically significant differences.Conclusion:1.FNATg and FNAC have good diagnostic accuracy for detection of metastaticcervical lymph nodes from papillary thyroid carcinoma.2.Combined FNATg and FNAC enhanced diagnostic accuracy of cervicallymph node metastatic carcinoma from papillary thyroid carcinoma.3.The cut-off level in determining positive FNATg should be greater than theserum Tg level.4.FNATg and FNAC may assist in preoperative diagnosis of cervical lymphnode metastatic carcinoma from papillary thyroid carcinoma, while FNATg may beused as surveillance index for postoperative follow-up of papillary thyroidcarcinoma.