Comparison of TIRADS [Thyroid imaging reporting and data system] with histopathology in assessment of thyroid nodules

Abstract

Introduction: The thyroid gland is an endocrine organ, which acts perfectly in maintaining the normal growth and activity of human beings. Factors causing a disturbance in its auto-regulatory mechanism leads to various thyroid function disorders that may or may not result in thyroid nodules. Malignancy comprises of less than 10% of all thyroid nodules on the basis of already established Breast Imaging Reporting and Data System (BIRADS) for breast nodules a categorization system of ultrasound features in thyroid nodules-the Thyroid Imaging Reporting and Data System (TIRADS) is suggested. Aims and Objectives: To assess validity of TIRADS in Indian population in differentiating thyroid nodules as benign and malignant taking histopathology as gold standard. Methodology: A descriptive study was done at JSS Hospital over a period of 18 months for 82 patients presenting with clinically palpable thyroid nodules and results were drawn assuming 50 percent sensitivity of TIRADS grading in differentiating the lesion as benign and malignant with an alpha error of 5 percent and a precision of 15 percent. All demographic data was summarized as proportion, mean, standard deviation and sensitivity, specificity, positive predictive value, negative predictive value were measured with 95% confidence interval. The inferential statistics were obtained using Chi-square and Cramer’s V tests. Results: 42.7 per cent cases were present in TIRADS II, 34.1 per cent in TIRADS III, 9.8 per cent in TIRADS IV A, 4.9percent each in TIRADS 1V B and C, 3.7 per cent in TIRADS V. TIRADS grading when compared with histopathology was found to have a sensitivity of 82.35 percent, a specificity of 92.30 percent, positive predictive value of 73.68 percent and a negative predictive value of 95.24 percent. Conclusion: TIRADS grading is a useful tool in pre operative evaluation and management, aids in deciding the timing of FNAC and when used along with it improves the diagnostic ability of a clinician in overall assessment of thyroid nodules.