From the Department of Radiology, Severance Hospital, Research Institute of Radiological Science (J.H.Y., E.K.K., H.J.M., J.Y.K.), and Biostastistics Collaboration Unit, Medical Research Center (H.S.L.), Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, 120-752 Seoul, Korea.
Radiology. 2015 Aug;276(2):579-87. doi: 10.1148/radiol.15142308. Epub 2015 Apr 3.
To compare the malignancy rates and the effectiveness of the Thyroid Imaging Reporting and Data System (TIRADS) for risk stratification of nodules with nondiagnostic results classified before and after application of the Bethesda System for Reporting Thyroid Cytopathology.
This retrospective study was approved by an institutional review board, with waiver of informed consent. A total of 763 patients with 790 thyroid nodules and nondiagnostic cytologic results were included (mean age ± standard deviation, 52.3 years ± 11.5), 485 nodules from the pre-Bethesda period (from March 2007 to December 2008) and 305 nodules from the post-Bethesda period (from May 2011 to May 2012). A TIRADS category was assigned to each thyroid nodule on the basis of the number of features that appeared suspicious for cancer at ultrasonography (US). Malignancy rates and TIRADS categories during the two periods were compared. Correlation between TIRADS category and malignancy risk between the two periods was evaluated and compared.
The malignancy rates of nodules with nondiagnostic cytologic results were not significantly different between the two periods (P = .148). Malignancy risk of TIRADS category 3, 4a, 4b, 4c, and 5 was 1.8%, 5.7%, 4.1%, 29.8%, and 16.7%, for the pre-Bethesda period, and 1.6%, 3.0%, 7.1%, 16.3%, and 25.0% for the post-Bethesda period, respectively. Near-perfect correlation was seen between the TIRADS category and malignancy risk in the post-Bethesda period (r = 0.961, P = .009), while no significant correlation was found in the pre-Bethesda period (r = 0.731, P = .161).
Malignancy risk stratification with TIRADS was more effective for nodules with nondiagnostic cytologic results classified according to the Bethesda System. When these Bethesda-classified nodules with nondiagnostic results are evaluated as TIRADS category 3 or 4a, they may be treated conservatively with follow-up US, but when other cytologic classifications are applied, follow-up US and fine- needle aspiration must be considered for nodules showing one or more features suspicious for cancer at US.
比较甲状腺影像报告和数据系统（TIRADS）在贝塞斯达系统报告甲状腺细胞学之前和之后用于分层诊断具有非诊断结果的结节的恶性率和有效性。
本回顾性研究经机构审查委员会批准，并豁免了知情同意。共纳入 763 例 790 个甲状腺结节和非诊断性细胞学结果的患者（平均年龄±标准差，52.3 岁±11.5 岁），其中 485 个结节来自贝塞斯达前时期（2007 年 3 月至 2008 年 12 月），305 个结节来自贝塞斯达后时期（2011 年 5 月至 2012 年 5 月）。基于超声（US）检查显示出可疑癌症的特征数量，为每个甲状腺结节分配 TIRADS 类别。比较两个时期的恶性率和 TIRADS 类别。评估和比较两个时期 TIRADS 类别与恶性风险之间的相关性。
两个时期具有非诊断性细胞学结果的结节的恶性率无显著差异（P=.148）。贝塞斯达前时期 TIRADS 类别 3、4a、4b、4c 和 5 的恶性风险分别为 1.8%、5.7%、4.1%、29.8%和 16.7%，贝塞斯达后时期分别为 1.6%、3.0%、7.1%、16.3%和 25.0%。贝塞斯达后时期 TIRADS 类别与恶性风险之间存在近乎完美的相关性（r=0.961，P=.009），而贝塞斯达前时期则无显著相关性（r=0.731，P=.161）。
使用 TIRADS 对根据贝塞斯达系统分类的具有非诊断性细胞学结果的结节进行恶性风险分层更为有效。当对这些根据贝塞斯达分类的具有非诊断性结果的结节进行评估为 TIRADS 类别 3 或 4a 时，可通过随访 US 进行保守治疗，但当应用其他细胞学分类时，对于显示出一个或多个可疑癌症 US 特征的结节，必须考虑进行随访 US 和细针抽吸。
