Efficacy of ultrasonic examination in predicting cervical lymph node metastasis in elderly patients with papillary thyroid carcinoma and analysis of related ultrasound signs

Objective: To explore the efficacy of ultrasonic examination for diagnosing cervical lymph node metastasis in elderly patients with papillary thyroidc arcinoma(PTC), and to analyze the related ultrasonographic characteristics. Methods: A total of 232 patients ≥60 years with PTC admitted to Ruijin Hospital, Shanghai Jiao Tong University School of Medicine between January 2021 and October 2021, were included in the retrospective analysis. According to postoperative pathology, the efficacy of ultrasound in predicting cervical lymph node metastasis were calculated. Multivariate logistic regression model was used to analyze the risk factor for cervical lymph node metastasis and risk factors were used to construct multi-factor model of risk for predicting cervical lymph node metastasis. Receiver operator characteristic (ROC) curves was used to evaluate the value of the model for predicting lymph node metastasis in elderly participants with PTC. Results: Rate of cervical lymph node metastasis was 30.6% (71 cases). The sensitivity, specificity, positive predictive va-lue and negative predictive value of ultrasound for cervical lymph node metastasis were 40.8%(29/232), 93.2% (150/232), 72.5% (29/40) and 78.1% (150/192). Univariate analysrs showed that the cervical lymph node metastasis rate was higher in patients with nodule size ≥10 mm, microcalcification, abundant color Doppler flow imaging (CDFI) blood flow, or the distance between the nodule and capsule <1 mm by preoperative ultrasound scanning (P<0.05). Multivariate logistic regression analysis demonstrated that preoperative ultrasonographic nodule size ≥10 mm (odds ratio[OR]=4.093, 95%CI: 1.933-8.666, P<0.001) and the distance between the nodule and capsule<1 mm (OR=2.177, 95%CI: 1.101-4.302, P=0.025) were independent risk factors for lymph node metastasis in elderly participants with PTC. The area under the curve(AUC) of combined these two independent risk factors for diagnosing cervical lymph node metastasis was 0.709. The AUC value was larger than either a risk factor. (AUC for the distance between the nodule and capsule<1 mm, was 0.602, and AUC for preoperative ultrasonographic nodule size ≥10 mm was 0.668). Conclusions: Proportion of cervical lymph node metastasis in the elderly patients with PTC. Large nodule size (≥10 mm) and close distance between the nodule and capsule (<1 mm) are independent risk factors for cervical lymph node metastasis for elderly patients with PTC