Comparison of S-Detect and thyroid imaging reporting and data system classifications in the diagnosis of cytologically indeterminate thyroid nodules.

Purpose: The aim of this study was to investigate the value of S-Detect for predicting the malignant risk of cytologically indeterminate thyroid nodules (CITNs). Methods: The preoperative prediction of 159 CITNs (Bethesda III, IV and V) were performed using S-Detect, Thyroid Imaging Reporting and Data System of American College of Radiology (ACR TI-RADS) and Chinese TI-RADS (C-TIRADS). First, Linear-by-Linear Association test and chi-square test were used to analyze the malignant risk of CITNs. McNemar's test and receiver operating characteristic curve were used to compare the diagnostic efficacy of S-Detect and the two TI-RADS classifications for CITNs. In addition, the McNemar's test was used to compare the diagnostic accuracy of the above three methods for different pathological types of nodules. Results: The maximum diameter of the benign nodules was significantly larger than that of malignant nodules [0.88(0.57-1.42) vs 0.57(0.46-0.81), P=0.002]. The risk of malignant CITNs in Bethesda system and the two TI-RADS classifications increased with grade (all P for trend<0.001). In all the enrolled CITNs, the diagnostic results of S-Detect were significantly different from those of ACR TI-RADS and C-TIRADS, respectively (P=0.021 and P=0.007). The sensitivity and accuracy of S-Detect [95.9%(90.1%-98.5%) and 88.1%(81.7%-92.5%)] were higher than those of ACR TI-RADS [87.6%(80.1%-92.7%) and 81.8%(74.7%-87.3%)] (P=0.006 and P=0.021) and C-TIRADS [84.3%(76.3%-90.0%) and 78.6%(71.3%-84.5%)] (P=0.001 and P=0.001). Moreover, the negative predictive value and the area under curve value of S-Detect [82.8% (63.5%-93.5%) and 0.795%(0.724%-0.855%)] was higher than that of C-TIRADS [54.8%(38.8%-69.8%) and 0.724%(0.648%-0.792%] (P=0.024 and P=0.035). However, the specificity and positive predictive value of S-Detect were similar to those of ACR TI-RADS (P=1.000 and P=0.154) and C-TIRADS (P=1.000 and P=0.072). There was no significant difference in all the evaluated indicators between ACR TI-RADS and C-TIRADS (all P>0.05). The diagnostic accuracy of S-Detect (97.4%) for papillary thyroid carcinoma (PTC) was higher than that of ACR TI-RADS (90.4%) and C-TIRADS (87.8%) (P=0.021 and P=0.003). Conclusion: The diagnostic performance of S-Detect in differentiating CITNs was similar to ACR TI-RADS and superior to C-TIRADS, especially for PTC.

Risk factors for posterior to right recurrent laryngeal nerve lymph node metastasis in papillary thyroid carcinoma.

OBJECTIVES: To identify the risk factors for posterior right recurrent laryngeal nerve lymph node metastasis (PRRLN-LNM) in papillary thyroid carcinoma (PTC). METHODS: We conducted a retrospective study of 389 patients with primary PTC who underwent right lobectomy or total thyroidectomy, and comprehensive right or bilateral central compartment dissection (CCD) with or without lateral neck dissection (LND) between January 2010 and May 2013 at the Department of Head and Neck Surgery, Institute of Micro-Invasive Surgery of Zhejiang University, Zhejiang, China. The clinicopathological findings were investigated, and relative risk factors for PRRLN-LNM were analyzed. RESULTS: Central compartment LNM were present in 50.9% (198/389), and PRRLN-LNM were present in 12.6% (49/389) of patients, wherein 3.1% (12/389) had PRRLN-LNM only. A multivariate analysis revealed that younger age (≤ 35 years), extrathyroidal extension (ETE), lateral compartment LNM, prelaryngeal LNM, pretracheal, and right paratracheal LNM were independent predictors of PRRLN-LNM. CONCLUSION: This study revealed that younger age (≤ 35 years), ETE, prelaryngeal LNM, lateral compartment LNM, and pretracheal and right paratracheal lymph nodes (anterior to the right recurrent laryngeal nerve [level VIa]), LNM were independent factors of PRRLN-LN (level VIb). Therefore, comprehensive right CCD should be routinely performed for such patients.