甲状腺乳头状癌颈部淋巴结转移FNA-Tg诊断标准值的探讨

Diagnostic value of thyroglobulin measurement in fine-needle aspiration biopsy for detecting lymph nodes metastasis in patients with papillary thyroid cancer

目的确立细针穿刺抽吸物洗脱液甲状腺球蛋白（FNA—Tg）浓度的测定诊断甲状腺乳头状癌颈部淋巴结转移的标准值。方法选择2010年8月至2012年6月期间63例甲状腺癌或术后随访中有淋巴结肿大者行超声引导下细针穿刺抽吸79枚可疑淋巴结，通过电化学发光免疫分析法（EcuA）测定FNA·Tg和血清甲状腺球蛋白含量（serumTg），分别选择FNA-Tg〉semmTg、mean1＋2sD（淋巴结无转移的FNA-Yg平均值加上2倍标准差）、10ng／ml、ROC曲线最佳工作点（optimaloperatingpoint，OOP）及1000ng/ml做为标准值，对比分析其敏感陛、特异性及ROC曲线下面积。结果5个阳性标准值的敏感胜分别为90．70％、90．70％、95．35％、90．70％及65．12％，其中当标准值为1000ns／ml时，敏感I生较低（P〈n05）。5组标准值的特异性分别为97．22％、91．67％、72．22％,97．22％及100％，当标准值为10ng／ml时，特异性较低（P〈n05），5个阳性标准值的ROC曲线下面积分别为0．940、0L912、0L838、0．940及n826，差异无统计学意义（P〉n05）。结论FNA—Tg／serumTg〉1可做为FNA-Tg阳性标准值，辅助诊断甲状腺乳头状癌颈部淋巴结转移。

Objective To investigate the diagnostic value of thyroglobulin measurement in fine-needle aspi- ration biopsy（FNA-Tg）. Methods This study included 63 patients with thyroid cancer or with enlarged lymph nodes during the follow-up from Aug. 2010 to Jun. 2012. Ultrasound-guided fine-needle aspiration was done in the 63 pa- tients with 79 suspicious enlarged lymph nodes. Then thyroglobnlin（Tg） in FNA washout fluid and serum Tg were as- sayed with electrochemil （ECLIA）. Diagnostic sensitivity, specificity and area under the ROC curve were evaluated according to 5 predetermined threshold levels ： FNA-Tg/serum-Tg 〉 l, mean ＋2SD of node-nega- tive patients, 10 ng/ml, optimal operating point of ROC curve and 1000 ng/ml. Results The sensitivity value was 90. 70%, 90. 70%, 95. 35%, 90. 70% and 65. 12% respectively on the 5 threshold level, significantly lower than those on the threshold level of 1000 ng/ml（P 〈0. 05）. The specificity value was 97. 22%, 91.67%, 72. 22%, 97. 22% and 100% （P 〉0. 05） on those threshold levels, significantly lower than those on the threshold level of 10 ng/ml （P 〈 0. 05）. The area under the ROC curve was 0. 940,0. 912,0. 838,0. 940 and 0. 826 respectively. There was no statistical difference（P 〉0.05）. Conclusion Selecting FNA-Tg/serum-Tg 〉 1 as a positive threshold value can be a secondary diagnosis of lymph nodes metastasis in patients with papillary thyroid cancer.