Clinical and sonographic features for the preoperative prediction of lymph nodes posterior to the right recurrent laryngeal nerve metastasis in patients with papillary thyroid carcinoma

Objective To evaluate clinical and sonographic features predictive of lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) metastasis in patients diagnosed with papillary thyroid carcinoma (PTC). Methods We retrospectively reviewed the clinical records and ultrasound (US) images of 479 consecutive PTC patients who received total thyroidectomy or right lobectomy with central neck dissection (CND) between October 2017 and October 2019. Univariate and multivariate analyses were performed to identify clinical and sonographic features associated with LN-prRLN metastasis. Receiver operating characteristic (ROC) analysis was applied to evaluate the efficacy of clinical and sonographic features in the preoperative prediction of LN-prRLN metastasis. Results Overall, 127 (26.5%) patients had LN-prRLN metastasis. Multivariate logistic regression analysis showed that age 1 cm ( p = 0.042; OR 1.702; 95% CI 1.019–2.842), microcalcifications ( p = 0.022; OR 1.980; 95% CI 1.104–3.551), and US-detected lateral compartment lymph node (LLN) metastasis ( p = 0.001; OR 2.578; 95% CI 1.500–4.430) were independent risk factors for LN-prRLN metastasis. ROC analysis revealed that the multivariate logistic regression model had good accuracy in predicting LN-prRLN metastasis, with an area under the ROC curve of 0.758. Conclusions Age less than 45 years, male sex, tumor diameter larger than 1 cm, microcalcifications, and US-detected LLN metastasis may preoperatively predict LN-prRLN metastasis.