A nomogram predicting contralateral central neck lymph node metastasis for papillary thyroid carcinoma.

Background and Objectives: Central compartment neck dissection (CCND) is recommended for patients with papillary thyroid carcinoma (PTC). However, whether to perform contralateral CCND remains unclear. An individualized estimation of the contralateral central neck metastasis (CNM) risk would assist in the tailoring of treatment for PTC patients. Methods: Consecutive patients who underwent bilateral CCND for unilateral PTC between 2012 and 2014 in a tertiary center were identified. The clinicopathological data of 142 patients were analyzed retrospectively. The variables that had clinical significance in the final multivariate logistic regression model were built into a nomogram to assess the risk of metastasis of the contralateral central compartment. This model was internally validated using bootstrap resampling. Results: This nomogram demonstrated good calibration and discrimination, with a concordance index of 0.834 (bootstrap corrected, 0.824). The variables with the greatest influence on the risk of contralateral CNM in this model included tumor size, the number of positive lymph nodes, and extranodal extension in the ipsilateral central neck. Conclusions: This nomogram integrates three variables to estimate an individualized risk of contralateral CNM in unilateral PTC patients. This model may assist in individual decision-making regarding contralateral CCND and help avoid the over-and under-treatment of PTC. (C) 2016 Wiley Periodicals, Inc.