Correlation between ultrasound-based TIRADS and Bethesda system for reporting thyroid-cytopathology: 2-year experience at a tertiary care center in India

Abstract

Background:In recent times, high-resolution ultrasound thyroid imaging has paved the way for significant transformation in clinical approach to thyroid nodule. There are several risk stratification systems in thyroid imaging, developed with an aim, not only to reduce the inter-observer variability but also to establish effective communication system. Thyroid image reporting and data system (TIRADS) classification system, which is similar to breast imaging reporting and data system for breast lesion, is the most useful of all. To our knowledge, there is just a handful published research articles available based on Indian population in this regard. In this article, we study the thyroid nodules using high-resolution ultrasound in Indian population and we try to correlate the TIRADS and Bethesda system for reporting thyroid cytopathology.Materials and Methods:This prospective study includes 184 patients studied over a period of 2 years (April 2015–April 2017). Patients having thyroid nodule in B-mode ultrasound and are scheduled to get a fine-needle aspiration cytology (FNAC) done. Bethesda classification of these nodules is tabulated in follow-up period simultaneously. By comparing these data, efficacy of TIRADS in differentiating benign from malignant nodules are assessed finally using accuracy, positive predictive value (PPV), cross-tabulation, and Chi-square tests.Results:Out of the 117 TIRADS 2 nodules, none turned out to be Bethesda IV or higher, which means none of these nodules turned out to be malignant. The risk of malignancy for TIRADS 2, TIRADS 3, TIRADS 4, and TIRADS 5 was 0, 2.2, 38.5, and 77.8%, respectively. The risk of malignancy percentage in our study is similar to those values obtained in other prominent studies.Conclusion:The probability of a particular nodule being malignant can be effectively inferred from the ultrasound-based TIRADS system with a certain level of confidence. Considering our results and other literature reviews, it be can be safely assumed that FNAC can be at least deferred in patients having TIRADS 2 nodules, which contribute to majority of newly detected cases. In our experience, there is a remarkable correlation exists between TIRADS ultrasound classification and Bethesda cytology, especially for benign nodules.

Comparison of Fine Needle Aspiration Cytology in Thyroid Lesions using The Bethesda System for Reporting Thyroid Cytopathology with Ultrasonography using Thyroid Imaging Reporting and Data System

“…Ideally, after a clinical evaluation and TFT, USG should be performed to stratify the thyroid lesions and FNA should be performed only on suspicious lesions. [12,13,14] Majority of the patients in our study were females. Other similar studies also reported predominance of female population presenting with thyroid lesions.…”

“…Other similar studies also reported predominance of female population presenting with thyroid lesions. [8,9,12] Increased prevalence of thyroid lesions in females, according to studies, might be related to hormonal influences of estrogen and progesterone. Rate of thyroid nodules increases proportionately with ionizing radiation or occupational exposures.…”

“…[12,13,14] that FNA smears should have at least six group of well-preserved, well-stained, and well-visualized thyroid follicular epithelial cells and each group should be composed of ten cells, preferably on a single slide. [5,15] Periakaruppan et al [12] observed 8% unsatisfactory cases on FNA in their study. The implied risk of malignancy on ND/USF is 5-10%, as laid down by TBSRTC.…”

Correlation Between Ultrasound-Based Acr Ti-Rads and Bethesda System for Reporting Thyroid-Cytopathology: A Prospective Study at Tertiary Care Center in Eastern India

“…In a prospective study on 184 patients by Periakaruppan et [12] al., the risk of malignancy for TIRADS categories 1, 2, 3, 4 and 5 was 0, 2.2, 38.5, and 77.8%, respectively. The malignancy risk for patients classified under TIRADS 4 was estimated at 17.5 times and those classified under TIRADS 5 were estimated at 35.4 times the risk for those rated as 3.…”

“…Even though the prevalence of thyroid [7,8] incidentalomas during FDG-PET imaging is 2.2 -2.3% but [7] the risk of malignancy is as high as 26.7% done for [9] metastasis work-up of cancer patients and screening of [ 1 0 , 1 1 ] cancer in healthy individuals. The possibility of malignancy is the main concern for the assessment of thyroid nodules and there are wide variations in the revealed extent of danger among the clinically or then again radiologically [12] recognized thyroid nodules.…”