Pediatric Adaptions Are Needed to Improve the Diagnostic Accuracy of Thyroid Ultrasound Using TI-RADS

Background/Purpose: Thyroid nodules are uncommon in pediatric patients. However, a thyroid nodule in a child poses a risk of malignancy up to 25-30%. A validated radiographic classification of thyroid nodules in adults, but not yet widely used in children, is Thyroid Imaging Reporting and Data System (TI-RADS). The purpose of this study was to determine the sensitivity, specificity and accuracy of TI-RADS in predicting thyroid malignancy for nodules with available cytopathology, and to compare the diagnostic accuracy to the current American Thyroid Association (ATA) guidelines.

Methods: A single institution retrospective review was performed of patients younger than 21 years who underwent thyroid nodule FNAB, and who had ultrasound imaging available. Two radiologists were blinded to the pathology and independently classified all biopsied thyroid nodules based on TI-RADS. The reliability of radiologists’ ratings was done using Spearman correlation. We then compared ATA guidelines to TI-RADS to determine the diagnostic sensitivity and specificity of both scoring systems in this cohort. All statistical analyses were conducted using SAS 9.4.

Results: 115 patients (median age 15.5 years, IQR (13-16.9), 90 females) with 138 nodules were retrospectively scored using TIRADS. There was moderate inter-rater agreement between radiologists (Kappa = 0.51; p<.0001). Using ATA guidelines, 82.6% of nodules were recommended for FNAB. Evaluating several potential TI-RADS criteria, 23.2%-68.1% of nodules were recommended for FNAB. Using TI-RADS  3 as in indication for FNA had 100% sensitivity with no missed suspicious or malignant nodules on cytology or pathology, respectively. Sensitivity, specificity, and accuracy for each system are displayed in Table 1.

Conclusions: Using TI-RADS for diagnostic management of pediatric thyroid nodules improves accuracy in predicting malignancy, thereby decreasing unnecessary biopsies. We recommend using TI-RADS  3 as an indication for FNA. Further efforts to validate TI-RADS for pediatric thyroid nodules are required.