[Establishment and validation of a nomogram model for evaluating the metastasis of lymph nodes posterior to the right recurrent laryngeal nerve in papillary thyroid carcinoma].

To explore the related factors of lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) metastasis in papillary thyroid carcinoma (PTC) and establish a nomogram model for evaluating LN-prRLN metastasis. The clinical data of patients with PTC who underwent surgery in the Department of Thyroid Surgery of the First Affiliated Hospital of Zhengzhou University from January 2020 to December 2021 were retrospectively analyzed. Multivariate logistic regression was used to analyze the related factors of LN-prRLN metastasis and construct a nomogram model for evaluating LN-prRLN metastasis. Meanwhile, the data of 120 patients from January to June 2022 were also collected for external verification. A total of 466 patients with PTC were enrolled, including 106 males and 360 females, and aged 44 (33, 53) years. There were 280 cases in the training group and 186 cases in the internal validation group, respectively. Multivariate logistic regression analysis showed that age (=0.966, 95%: 0.938-0.996, =0.027), tumor size (=1.048, 95%: 1.001-1.098, =0.043), multifocality (=2.459, 95%: 1.268-4.767, =0.008), right central lymph node metastasis reported by ultrasound (=3.099, 95%: 1.255-7.651, =0.014), extrathyroid extension (=3.561, 95%: 1.255-10.102, =0.017) and serum thyroglobulin level (=1.010, 95%: 1.001-1.018, =0.032) were related factors for LN-prRLN metastasis. The area under the curve (AUC) values of receiver operating characteristic (ROC) curves of the training group, internal validation group and external validation group were 0.765 (95%: 0.691-0.840), 0.747 (95%: 0.657-0.837) and 0.754 (95%: 0.639-0.869), respectively. Dissection of the LN-prRLN is recommended for young PTC patients with large tumor size, multifocality, right central lymph node metastasis reported by ultrasound, extrathyroid extension and high serum thyroglobulin level.