Correlation between Thyroid Imaging Reporting and Data System and Bethesda System of Reporting of Thyroid Cytopathology of Thyroid Nodule: A Single Center Experience

Correlation of ultrasound-based TIRADS and the Bethesda system for reporting of thyroid cytopathology: A study in a tertiary care centre

BACKGROUND

The age-standardised incidence rate of thyroid cancer in India is 1 in 416 in the general population. This increased incidence has mainly been attributed to improved detection methods for small thyroid lesions. Two such methods are the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TIRADS) and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC).

AIMS AND OBJECTIVES

To study the correlation between ACR TIRADS and TBSRTC, and between each system and the final histopathological report.

MATERIALS AND METHODS

Thyroid cytopathology cases were retrieved for the period January 2019 to July 2022. For each case, the TIRADS score and Bethesda category were noted. Histopathology specimens were also traced.

RESULTS

The study comprised 1100 cases, with 955 female and 145 male patients (M:F = 1:6.59), and ages ranging between 7 and 85 years. The TIRADS scoring was available for 1036 cases. Histopathology was available for 231 cases. There was a significant correlation between TIRADS and TBSRTC, with a p-value of 0.000 and a substantial Kappa agreement of 0.688. Both TIRADS and TBSRTC also had significant correlations with the histopathology data, with a p-value of 0.000 for each. The sensitivity values for TBSRTC and TIRADS were 69.4% and 65.8%; specificity, 99.3% and 96.5%; positive predictive value (PPV), 98.3% and 91.8%; and negative predictive value (NPV) 84.7% and 84.4%, respectively. The risk of malignancy (ROM) was also calculated and was found to be high, especially for TBSRTC II, III, IV and V (11.3%, 20%, 61.5%, 97.4% respectively) and TIRADS 2 and 3 (10.3% and 29.6% respectively).

CONCLUSION

The TIRADS and TBSRTC systems of categorisation of thyroid lesions are concordant and could help improve the overall survival rate of patients with thyroid malignancies.

Correlation of the ultrasound thyroid imaging reporting and data system with cytology findings among patients in Uganda

BACKGROUND

Ultrasonography is a noninvasive modality for the initial assessment of thyroid nodules. The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) has demonstrated good performance in differentiating malignant thyroid nodules. However, the combination of ACR TI-RADS categories and cytology has not been studied extensively, in Uganda. The study aims to correlate ACR TI-RADS with cytology among patients referred for US-guided fine-needle aspiration at Mulago National Referral Hospital.

METHODS

This was a hospital-based cross-sectional study that recruited 132 patients with thyroid nodules. Spearman's correlation was used to establish a relationship between TI-RADS and cytology findings. The diagnostic accuracy of TI-RADS was assessed using sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios.

RESULTS

Of 132 study participants, 90% (n = 117) were females, and the mean age was 41 ± 13 years. One hundred sixty-one thyroid nodules were analyzed. More than half of the thyroid nodules (54.7%, n = 87) were solid or almost solid, 96.9% (n = 154) were shaped wider than tall, 57.2% (n = 91) had smooth margins, 83.7% (n = 133) were hyperechoic or isoechoic, and 88.7% (n = 141) had no echogenic foci. TI-RADS 3 was the most common at 42.9% (n = 69). The proportions of malignancy for TI-RADS 4 and TI-RADS 5 were 73.3% and 85.7%, respectively. The correlation between ACR TI-RADS and the Bethesda system of thyroid classification scores was r = 0.577. The sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of ACR TI-RADS were 90.9%, 98.5%, 90%, 99.3%, 62.3, and 0.1, respectively.

CONCLUSION

We found that ACR TI-RADS classification is an appropriate and noninvasive method for assessing thyroid nodules in routine practice. It can safely reduce the number of unnecessary fine-needle aspiration in a significant proportion of benign thyroid lesions. Thyroid nodules classified as TI-RADS 3 should be followed routinely. ACR TI-RADS should be standardized as the screening tool in resource-limited areas.

The relationship between ultrasound-based TIRADS and BETHESDA categories in patients undergoing thyroid biopsy

The TIRADS is a scoring system used for the selection of nodules for FNA and classification of the risk of malignancy based on ultrasound characteristics. The BETHESDA is a standard reporting system used for the classification of FNA results based on six criteria with risks for malignancy. The objective of this study was to evaluate the relationship between TIRADS and BSRTC classifications in patients undergoing thyroid biopsy. A total of 350 consecutive patients were retrospectively evaluated using TIRADS and BETHESDA reporting systems for determining preoperative diagnosis of thyroid nodules. Patients' demographics, size, echogenicity and contour status of the nodules, TIRADS and BETHESDA scores were recorded and analyzed. Data obtained in this study were expressed as mean, standard deviation, frequency and percentage descriptive statistics. The mean age of the patients was 49.03 ± 17.58 years. The mean nodule size was measured as 20.56 ± 10.47 mm. TIRADS TR3 category was found in 165 (47.14%), TR4 in 154 (44%) and TR5 in 31 (8.86%) patients, while BETHESDA II category was found in 288 (82.28%), BETHESDA III category in 1 (0.29%), BETHESDA IV category in 19 (5.43%), BETHESDA V in 37 (10.57%) and BETHESDA VI in 5 (1.43%) patients. There was a general concordance between BETHESDA and TRIADS categories. The most significant concordance was found between BETHESDA IV and TR4 categories (84.21%). Combined use of TRIADS and BETHESDA can be efficiently used to provide the most accurate results for making preoperative diagnosis of thyroid nodules and to determine the risk of malignancy.