From the Guidelines
A TR3 score on a thyroid ultrasound indicates an intermediate suspicion for malignancy in a thyroid nodule, and fine needle aspiration (FNA) biopsy is typically recommended if the nodule is 1.5 cm or larger, as per the Thyroid Imaging Reporting and Data System (TI-RADS) 1. The TR3 classification is based on specific ultrasound features such as mild hypoechogenicity, solid composition, or irregular margins that raise some concern but don't place the nodule in a high-risk category.
- The risk of malignancy for TR3 nodules is approximately 5-10% 1.
- The management of TR3 nodules should be individualized, taking into account the size of the nodule, patient preferences, and other clinical factors.
- For smaller nodules, ultrasound follow-up in 1-3 years is generally appropriate, as the risk of malignancy is lower and the potential harms of biopsy and overtreatment should be avoided 1.
- The American Thyroid Association guidelines recommend classifying differentiated thyroid carcinomas (DTCs) as low-, intermediate-, and high-risk, which helps determine the need for radioiodine treatment and tailor postoperative management for DTC 1.
- However, this risk assessment is based on postoperative characteristics and cannot be applied to medullary carcinoma or other types of thyroid cancer.
- Patients with TR3 nodules should discuss the specific characteristics of their nodule with their healthcare provider to determine the most appropriate management plan, considering the potential benefits and harms of different approaches 1.
From the Research
TR3 Score on Thyroid Ultrasound
- The TR3 score is part of the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) used to categorize thyroid nodules based on their sonographic features 2, 3, 4.
- A study published in 2021 found that adjusting the size threshold for TR3 nodules from 1.5 cm to 1.0 cm would result in seven additional malignant nodules and 118 additional benign nodules receiving a recommendation for follow-up 2.
- Another study published in 2024 found that the rate of malignancy increased as the TIRADS score increased, with 21.7% of TR3 nodules being malignant 3.
- The ACR TI-RADS scoring system has been shown to be an effective risk classification system for thyroid nodules, providing 75% accuracy in predicting malignancy 3.
- Comparison of different thyroid risk categorization systems found that ACR TI-RADS recommends fewer biopsies compared to other guidelines, such as the American Thyroid Association (ATA) and European Thyroid Imaging Reporting and Data System (EU-TIRADS) 4.
Characteristics of Malignant Nodules with TR3 Score
- A study published in 2021 found that 7 out of 16 malignant nodules that were 1 cm or larger were classified as TR3 nodules 2.
- The same study found that these TR3 nodules would not be biopsied under the current ACR TI-RADS recommendations, but would undergo US follow-up 2.
- Another study published in 2024 found that TR3 nodules had a malignancy rate of 21.7%, which is lower than TR4 and TR5 nodules 3.
Clinical Implications of TR3 Score
- The TR3 score can be used to guide clinical management of thyroid nodules, with nodules classified as TR3 potentially requiring follow-up ultrasound examinations 2, 4.
- The ACR TI-RADS scoring system, including the TR3 score, can help reduce the number of unnecessary biopsies and improve patient outcomes 3, 4.