Assessment of thyroid nodule by ultrasound elastography and fine needle aspiration cytology

Abstract

Background: According to the 2022, Health Statistics in Mongolia, the incidence of thyroid cancer is increasing annually and it is mostly diagnosed at a late stage, which indicates the importance of early cancer detection and diagnosis. Studies comparing elastography and fine needle aspiration cytology (FNAC) in thyroid tumor have not been conducted to date which we based on to conduct the current study. Aim: We aimed to determine the malignancy of thyroid nodules by ultrasound elastography and compare it with fine needle cytology. Materials and Methods: The study was conducted by using a cross sectional method of hospital-based analytical study involving 97 patients with thyroid nodules who attended the Department of Endocrinology at the State First Central Hospital during between May and October, 2020. Thyroid ultrasonography was performed on all participants in the study, and elastography and fine-needle cytometry were performed on those with TR3, TR4, and TR5 nodules classified by the international TI-RADS classification. Results: The average age of the 97 subjects in our study was 50±10.7 years (16-74), and in terms of gender, 91 (93.8%) were women and 6 (6.2%) were men. According to the Rago Elastography of Thyroid nodules, 15 (15.5%) had a score of 1 or benign, 67 (69.1%) had a score of 2 or benign, 7 (7.2%) had a score of 3 or unclear, and 7 (7.2%) had a score of 4 or malignant, and 1 (1%) was a 5-point or malignant nodule. According to the Bethesda classification of fine needle cytology, 25 (25.8%) nodules were undiagnosable or class I, 56 (57.7%) were benign or class II, 6 (6.2%) were indeterminate or class III, and 3 (3.1%) were follicular neoplasm or class IV, 3 (3.1%) were suspicious for cancer or class V, and 4 (4.1%) were malignant or class VI. Malignant and benign nodules defined by Rago elastography were statistically significantly correlated with those defined as benign and malignant by fine needle cytology (p=0.0001). Conclusion: Ultrasound elastography is statistically significant in identifying malignant thyroid nodules TR3, TR4, and TR5. Specificity and sensitivity of elastography and fine needle cytology for evaluation of thyroid nodule malignancy were similar (kappa 1.0, p=0.0001).