Assessment of Malignancy Risk in Thyroid Nodules Using a Practical Ultrasound Predictor Model: “Alpha Score”

Abstract

Objective: The aim of this study was to develop a simple predictor model to diagnose malignancy by using ultrasound features of thyroid nodules and the association with cytopathological diagnosis obtained by fine needle aspiration. Materials and Methods: The likelihood of malignancy from ultrasound features was assessed in thyroid nodules obtained by fine-needle aspiration biopsy (FNAB) according to cytopathological findings reported using Bethesda System. A score was developed depending on the presence of each ultrasound feature evaluated. Results: 429 nodules were assessed, 103 (24%) were malignant. The following ultrasound features were associated with malignancy, according to the logistic regression analysis and were assigned a score of 0, +1, +2 depending on the presence or absence of each one: hypoechogenicity, solid appearance, irregular margins, microcalcifications, absence of a halo, diameter of ≥10 mm and intranodular vascular flow. The area under the curve of the proposed model was 0.900, demonstrating its predictive capacity. 4 risk categories were stablished based on the score obtained. Malignant nodules scored higher than the benign nodules (7.24 ± 1.87 vs. 3.74 ± 1.83). Conclusions: The proposed predictive model demonstrated to be useful and easy to apply when stratifying thyroid nodule risk of malignancy using presented US features and applying the proposed risk categories to increase the accuracy at selecting nodules that need to be studied with FNA.

Elastography of the thyroid nodule, cut-off points between benign and malignant lesions for strain, 2D shear wave real time and point shear wave: a correlation with pathology, ACR TIRADS and Alpha Score

“…On the contrary, other authors report that the diagnostic accuracy of the specificity and PPV were inferior to conventional ultrasound by itself (28), or that neither TE alone nor in combination with US showed better performance in diagnosing thyroid cancer (34). We disagree with these latter conclusions, as mentioned before, in our experience and according to the results of past publications (23,24), TE and ultrasound both individually and together present reliable results that correlate well with Bethesda, histopathology and prediction scales (such as ACR TI-RADS or AS).…”

“…Here we present an analysis of the diagnostic capacity of TE to differentiate malignant and benign TNs and propose C/O to enable such distinction; the main results can be found on Table 1 and Table 7 showcases the comparison of the diagnostic performance of TE against commonly used prediction scales and our own AS scale, that has been previously reported (23,24). One of the first reports on the use of TE reported an exceptionally high AUC of 0.94 (16), but later studies did not managed to reproduce it; we believe that one reason lies with the fact that there is a lot of diversity in the different measurements and parameters that can be obtained in TE such as the definition of ROI, the type of SR, the C/O and its values with Emax, Emean, the elasticity scale settings, and the scan planes used.…”

“…Finally, when assessing TE against cytopathology (Bethesda) and commonly used prediction scales such ACR TI-RADS and our own scale (AS), we found good correlation between them as shown in Table 7. Our recommendation, which was already widely discussed in previous publications (23,24), is that two prediction classifications should be used. In our experience, when reporting ACR TI-RADS and AS together, classification of the TNs becomes easier; this has been supported by commentaries of fellow clinicians (23,24).…”

“…Our recommendation, which was already widely discussed in previous publications (23,24), is that two prediction classifications should be used. In our experience, when reporting ACR TI-RADS and AS together, classification of the TNs becomes easier; this has been supported by commentaries of fellow clinicians (23,24). Furthermore, if we add TE values to these analyses, as an additional measure of malignancy prediction, physicians would be able to properly select potentially malignant TN that should have FNAB, microcarcinomas that should have active surveillance, or potentially benign TN that should not be punctured, thus decreasing the rate of unnecessary procedures or expenditure (7).…”

“…At the Institute of Radiology and Interventionism, Alpha Imagen, Quito, Ecuador, from January 2020 to December 2021, 196 TNs were analyzed, all of them had fine needle aspiration biopsy (FNAB) by different specialists; all TNs were classified by ultrasound using two types of malignancy predictors: ACR TI-RADS and Alpha Score (AS), a previously reported US prediction score validated in Latin-American countries (23,24). Of those, 170 TNs with benign (Bethesda II) or malignant results (Bethesda V and VI, verified with post-surgical histopathological results) were selected.…”