Division of Endocrinology and Metabolism, Department of Internal Medicine, Soonchunhyang University Hospital, Soonchunhyang University College of Medicine, 59 Daesagwan-ro, Yongsan-gu, Seoul, 140-743, Republic of Korea.
Elim Thyroid Clinic, Seoul, South Korea.
BMC Cancer. 2020 Feb 12;20(1):118. doi: 10.1186/s12885-019-6437-z.
Although shear wave elastography (SWE) is reported to be useful in detecting malignant thyroid nodules, it shows a wide range of cut-off values of elasticity index (EI) in detecting malignant nodules. The cause of discrepancy remains unclear. Fibrosis of the tumors is known to increase the EI in SWE, and matching of SWE and surgical histopathology has not been fully illustrated in thyroid cancer. We aimed to evaluate the reproducibility of the new total nodular region of interest (ROI) method excluding the subjective features of focal circular ROI placement and to determine the lesion that causes the elevation of EI on SWE and on histopathology.
A total of 29 thyroid cancers from 28 patients were included. We evaluated the reproducibility of EI in the new total nodular ROI using Q-Box Trace program and compared the EI in focal nodular ROI using a 3-mm circular area. We analyzed the correlation between fibrosis and EI.
The coefficient of variation (CV) of the intrarater assay was significantly lower in total nodular ROI than in focal nodular ROI within the image in rater 1 (1.7% vs. 13.4%, p < 0.001) and in rater 2 (1.4% vs. 16.9%, p < 0.001) and in different images in rater 1 (7.6% vs. 12.3%, p = 0.040) and in rater 2 (7.5% vs. 19.8%, p = 0.004). Moreover, CV of the interrater assay showed similar results (14.9% vs. 19%, p = 0.030). Interrater intraclass correlation coefficient showed better agreement in total nodular ROI than in focal nodular ROI (0.863 vs. 0.783). The degree of fibrosis on histopathology showed significant correlations with EI (E, p < 0.001; E, p = 0.027), and the location of fibrosis was concordant with the high EI area on SWE.
Our study revealed that the new total nodular ROI method showed higher reproducibility and better agreement in intra- and interrater assay than the focal nodular ROI method, suggesting a valuable and standardized method in clinical practice. Moreover, our results showed that fibrosis in the histopathology increased EI on SWE and might lead to the discrepancy of the cut-off values in detecting thyroid cancer.
尽管剪切波弹性成像（SWE）已被证实可用于检测甲状腺恶性结节，但在检测恶性结节时，其弹性指数（EI）的截断值范围较宽。造成这种差异的原因尚不清楚。肿瘤纤维化已知会增加 SWE 中的 EI，并且 SWE 与手术组织病理学的匹配尚未在甲状腺癌中得到充分说明。我们旨在评估新的全结节感兴趣区域（ROI）方法排除焦点圆形 ROI 放置的主观特征的可重复性，并确定在 SWE 和组织病理学上导致 EI 升高的病变。
共纳入 28 例患者的 29 例甲状腺癌。我们使用 Q-Box Trace 程序评估了新的全结节 ROI 中 EI 的可重复性，并比较了使用 3mm 圆形区域的焦点结节 ROI 中的 EI。我们分析了纤维化与 EI 的相关性。
在评分者 1 （1.7%对 13.4%，p<0.001）和评分者 2 （1.4%对 16.9%，p<0.001）的图像内，以及评分者 1 （7.6%对 12.3%，p=0.040）和评分者 2 （7.5%对 19.8%，p=0.004）的不同图像内，全结节 ROI 的组内变异系数（CV）明显低于焦点结节 ROI。此外，组间 CV 也显示出相似的结果（14.9%对 19%，p=0.030）。组间内评分者的组内相关系数显示，全结节 ROI 比焦点结节 ROI 具有更好的一致性（0.863 对 0.783）。组织病理学上纤维化的程度与 EI 显著相关（E，p<0.001；E，p=0.027），纤维化的位置与 SWE 上高 EI 区域一致。
本研究表明，与焦点结节 ROI 方法相比，新的全结节 ROI 方法在组内和组间评估中具有更高的可重复性和更好的一致性，提示在临床实践中具有重要价值和标准化方法。此外，我们的研究结果表明，组织病理学上的纤维化增加了 SWE 上的 EI，可能导致在检测甲状腺癌时的截断值差异。
