PURPOSE Given the large number of patients with thyroid nodules, improvement of the specificity of current ultrasound-based thyroid nodule classification systems (ATA, EU-TIRADS, and ACR-TIRADS) is warranted to reduce the number of diagnostic thyroidectomies. Thyroid scintigraphy has been shown to demonstrate hyperfunctional nodules, associated with a low malignancy risk, in euthyroid patients. However, it is not known if thyroid scintigraphy could improve specificity of current classification systems. The aim of this study, therefore, was to determine the frequency of hyperfunctional nodules among those nodules in need of fine needle aspiration cytology (FNA) according to current classification systems and to test if nodule functional status is associated with sonographic features. METHODS Five hundred sixty-six euthyroid patients (TSH 0.55-4.20 μU/ml) presenting for thyroid nodule workup including thyroid sonography and scintigraphy at our department between 09/2013 and 02/2018 were included in this retrospective study. All nodules > 10 mm were classified according to ATA, EU-TIRADS, and ACR-TIRADS and correlated to their functional status as assessed by 99mTc-pertechnetate scintigraphy. RESULTS Ultrasound detected 1029 thyroid nodules ≥ 10 mm, including 545 nodules ≥ 15 mm. Prevalence of hyperfunctional nodules among those with recommendation for FNA according to ATA 2015, EU-TIRADS, and ACR-TIRADS was 6.4%, 6.9%, and 6.5% for nodules ≥ 10 mm and 7.2%, 7.6%, and 7.5% only considering nodules ≥ 15 mm. No sonographic feature was correlated to hyperfunctionality of nodules. CONCLUSION In euthyroid patients, thyroid scintigraphy demonstrates hyperfunctionality, which cannot be predicted by ultrasound, in up to 6.9% of nodules in need of FNA according to ultrasound-based classifications. Given the known low risk of malignancy in hyperfunctional nodules, thyroid scintigraphy can lower the frequency of fine needle aspirations and-potentially-the frequency of diagnostic hemithyroidectomies in euthyroid patients.

中文翻译：

---

根据ATA 2015，EU-TIRADS和ACR-TIRADS，在需要细针穿刺细胞学检查的甲状腺功能亢进症中的患病率较高。

目的鉴于大量甲状腺结节患者，有必要改善当前基于超声的甲状腺结节分类系统（ATA，EU-TIRADS和ACR-TIRADS）的特异性，以减少诊断性甲状腺切除术的数量。甲状腺闪烁扫描已显示出在甲状腺功能正常的患者中显示出功能性结节，伴有低恶性肿瘤风险。但是，尚不知道甲状腺闪烁显像术是否可以改善当前分类系统的特异性。因此，本研究的目的是根据当前的分类系统，确定需要细针穿刺细胞学检查（FNA）的结节中超功能结节的频率，并测试结节功能状态是否与超声特征相关。方法566例甲状腺功能正常的患者（TSH 0.55-4。这项回顾性研究包括了在09/2013年至02/2018年间在我科进行甲状腺结节检查（包括甲状腺超声检查和闪烁显像）的20μU/ ml）。根据ATA，EU-TIRADS和ACR-TIRADS对所有大于10 mm的结节进行分类，并通过99mTc-高tech闪烁显像仪评估其功能状态。结果超声检测到1029个≥10 mm的甲状腺结节，包括545个≥15 mm的结节。仅考虑ATA 2015，EU-TIRADS和ACR-TIRADS推荐的FNA者中，功能亢进性结节的发生率分别为6.4％，6.9％和6.5％，仅考虑≥10 mm的结节结节≥15 mm。没有超声特征与结节功能亢进相关。结论在甲状腺功能正常的患者中，甲状腺闪烁显像显示功能亢进，根据基于超声的分类，多达6.9％的需要FNA的结节无法通过超声进行预测。鉴于已知功能亢进结节的恶性风险较低，甲状腺闪烁显像可降低正常甲状腺患者细针穿刺的频率，并有可能降低诊断性半甲状腺切除术的频率。