本研究旨在验证韩国甲状腺放射学会（KSThR）提出的风险分层系统（RSS）和颈部淋巴结（LNs）活检标准。本回顾性研究纳入了2006年12月至2015年6月期间连续接受甲状腺癌患者的淋巴结活检、超声检查和计算机断层扫描（CT）的患者群。根据当前基于超声和CT的RSS和KSThR建议的颈部淋巴结活检的大小阈值，将淋巴结分为可能良性、不确定和可疑三类。计算了诊断性能和不必要活检率。共分析了228位患者（平均年龄±标准偏差为47.4岁±14）中的277个淋巴结（53.1%转移性）。在超声方面，三个类别的恶性风险显著不同（所有P < 0.001）；然而，CT检测到的可能良性和不确定淋巴结的恶性风险相对较低（P = 0.468）。综合超声和CT标准可以将三个类别的恶性风险分层（所有P < 0.001），并与仅使用超声相比，降低不确定淋巴结的比例（从20.6%降低至14.4%），降低不确定淋巴结的恶性风险（从31.6%降低至12.5%）。在所有基于影像的分类中，淋巴结大小对恶性风险没有影响（短径[SD] ≤ 5 mm的淋巴结与SD > 5 mm的淋巴结比较，P ≥ 0.177）。仅涵盖可疑淋巴结的标准显示出较高的特异性和较低的不必要活检率，同时在所有成像模式中保持敏感性。超声和CT的综合评估有助于降低不确定淋巴结的比例和其中的恶性风险。淋巴结大小不影响淋巴结的恶性风险，而将不确定淋巴结加入活检候选者中在所有成像模式中检测淋巴结转移上没有优势。版权所有©2023韩国放射学学会。

This study aimed to validate the risk stratification system (RSS) and biopsy criteria for cervical lymph nodes (LNs) proposed by the Korean Society of Thyroid Radiology (KSThR).This retrospective study included a consecutive series of preoperative patients with thyroid cancer who underwent LN biopsy, ultrasound (US), and computed tomography (CT) between December 2006 and June 2015. LNs were categorized as probably benign, indeterminate, or suspicious according to the current US- and CT-based RSS and the size thresholds for cervical LN biopsy as suggested by the KSThR. The diagnostic performance and unnecessary biopsy rates were calculated.A total of 277 LNs (53.1% metastatic) in 228 patients (mean age ± standard deviation, 47.4 years ± 14) were analyzed. In US, the malignancy risks were significantly different among the three categories (all P < 0.001); however, CT-detected probably benign and indeterminate LNs showed similarly low malignancy risks (P = 0.468). The combined US + CT criteria stratified the malignancy risks among the three categories (all P < 0.001) and reduced the proportion of indeterminate LNs (from 20.6% to 14.4%) and the malignancy risk in the indeterminate LNs (from 31.6% to 12.5%) compared with US alone. In all image-based classifications, nodal size did not affect the malignancy risks (short diameter [SD] ≤ 5 mm LNs vs. SD > 5 mm LNs, P ≥ 0.177). The criteria covering only suspicious LNs showed higher specificity and lower unnecessary biopsy rates than the current criteria, while maintaining sensitivity in all imaging modalities.Integrative evaluation of US and CT helps in reducing the proportion of indeterminate LNs and the malignancy risk among them. Nodal size did not affect the malignancy risk of LNs, and the addition of indeterminate LNs to biopsy candidates did not have an advantage in detecting LN metastases in all imaging modalities.Copyright © 2023 The Korean Society of Radiology.