NASHVILLE — The 2017 American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS) is effective at prediagnostic classification of thyroid nodules’ malignancy risk in children. This research was presented at the 61st Society for Pediatric Radiology Annual Meeting & Postgraduate Course, held May 15-19, 2018 in Nashville, Tennessee.
This study included a retrospective review of 74 thyroid nodules (median size, 1.9 cm; IQR 1.3-2.8) that had been diagnosed histologically in 62 children (6 male, 56 female).
Using the ACR TI-RADS lexicon, a pair of radiologists assigned independent ratings to the ultrasound images regarding composition, shape, echogenic foci, echogenicity, and margins. To measure both inter- and intra-observer agreement, kappa coefficients were used.
Nodule features were assigned points that were summed to give the TI-RADS level. This level ranged from 1 to 5, or benign to high-suspicion, respectively. Overall ability of TI-RADS to predict malignancy was then estimated using generalized linear mixed effects models.
There were 20 malignant and 54 benign nodules. Of these, 36 nodules were classified as TI-RADS 5 (48.7%; 17 malignant, 19 benign), 24 as TI-RADS 4 (32.4%; 2 malignant, 22 benign), 6 as TI-RADS 3 (8.1%; 0 malignant, 6 benign), 4 as TI-RADS 2 (5.4%; 0 malignant, 4 benign), and 4 as TI-RADS 1 (5.4%, 1 malignant, 3 benign).
For all parameters, kappa values for inter-observer agreement ranged from 0.25 to 0.84 (P =.02 to <.0001) and from 0.46 to 0.94 (P <.0001) for intra-observer agreement. Each incremental increase of 1 TI-RADS point corresponded with a 2.63 times greater likelihood of malignancy (P =.03).
Each incremental 1-cm size increase in thyroid nodules corresponded with a 1.69 times greater likelihood of malignancy (P =.03). The TI-RADS scale correlated only slightly with a malignant diagnosis after adjusting for nodule size (P =.07). With the exception of 1 patient, TI-RADS rated all malignant nodules as TI-RADS 4 or 5 (19 out of 20).
The 2017 ACR TI-RADS was created to categorize malignant thyroid nodules in children. This study sought to evaluate ACR TI-RADS’ effectiveness in doing so.
The study researchers conclude that “ACR TI-RADS allows for appropriate stratification of malignancy risk for thyroid nodules in children prior to tissue diagnosis. Subcentimeter nodules must be assessed with caution and additional nodules in patients with at least one other TI-RDS 4 or 5 must be regarded with suspicion.”
Lim-Dunham JE, Erdem Toslak I, Reiter MP, Martin B. Malignancy risk stratification of pediatric thyroid nodules using ACR Thyroid Imaging, Reporting and Data System (ACR TI-RADS). Poster presentation at: SPR 2018 Annual Meeting & Postgraduate Course; May 15 – May 19, 2018; Nashville, TN. Poster P132.