Background

The aim of this study was to evaluate the role of dual isotope ¹²³Iodine/^99mTc-MIBI thyroid scintigraphy (IMS) in discriminating between malignant and benign lesions in indeterminate nodules using quantitative analysis methods.

Methods

Thirty-five consecutive patients with thyroid nodules of indeterminate or non-diagnostic cytology and cold on ¹²³Iodine scintigraphy (10 Bethesda I, 24 Bethesda III-IV, 1 in which cytology was impossible) underwent IMS between 2017 and 2019 with uptake quantification at two time points ahead of thyroidectomy: early and late. Images were analyzed by two blinded physicians.

Results

Twelve nodules were malignant and 23 benign on histopathology. Mean uptake values were lower in benign than in malignant nodules at both time points: early, 8.7 ± 4.1 versus 12.9 ± 3.5 (P = 0.005); and late, 5.3 ± 2.7 versus 7.7 ± 1.1 (P = 0.008). Interobserver reproducibility was excellent. The intraclass correlation coefficient was 0.86 in benign and 0.92 in malignant lesions for early uptake result (ER) and 0.94 and 0.85 respectively for late uptake result (LR). The optimal LR cut-off to exclude a diagnosis of malignancy was set at 5.9 . The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of this cut-off were, respectively, 100%, 65.2%, 60%, 100% and 77.1%.

Conclusion

Despite some study limitations, quantitative analysis of ^99mTc-MIBI thyroid scintigraphy had a good reproducibility, which could help to rule out malignancy in non-diagnostic or indeterminate thyroid nodules and thereby reducing the number of patients undergoing unnecessary surgery when LR is below 5.9.

中文翻译：

---

定量双同位素 123 碘/99mTc-MIBI 闪烁显像：一种排除甲状腺结节恶性肿瘤的新方法

背景

本研究的目的是评估双同位素¹²³碘/ ^99m Tc-MIBI 甲状腺闪烁显像 (IMS) 在使用定量分析方法区分不确定结节的恶性和良性病变中的作用。

方法

^{在 2017 年至 2019 年期间，连续 35 名甲状腺结节患者在123}次碘闪烁显像（10 名 Bethesda I、24 名 Bethesda III-IV、1 名无法进行细胞学检查）时细胞学检查未确定或未确诊且冷的患者在 2017 年至 2019 年间接受了 IMS，并在 2甲状腺切除术前的时间点：早期和晚期。图像由两名不知情的医生分析。

结果

12 个结节在组织病理学上为恶性，23 个为良性。在两个时间点，良性结节的平均摄取值低于恶性结节：早期，8.7  ±  4.1 vs 12.9  ±  3.5 ( P  =  0.005)；和晚期，5.3  ±  2.7 对 7.7  ±  1.1 ( P  = 0.008)。观察者间的重现性非常好。早期摄取结果（ER）的组内相关系数为0.86，恶性病变为0.92，晚期摄取结果（LR）分别为0.94和0.85。排除恶性肿瘤诊断的最佳 LR 截止值为 5.9。该临界值的敏感性、特异性、阳性预测值、阴性预测值和准确度分别为100%、65.2%、60%、100%和77.1%。

结论

^{尽管存在一些研究局限性，但99m} Tc-MIBI 甲状腺闪烁显像的定量分析具有良好的重现性，这有助于排除非诊断或不确定甲状腺结节的恶性，从而减少 LR 低于 5.9 时接受不必要手术的患者数量。