Study: Tool for thyroid nodule evaluation misses thyroid cancers in children

A thyroid nodule is a solid or fluid-filled lump that forms within the thyroid gland. Most thyroid nodules that develop in children are benign and don’t cause symptoms. However, about 20 percent of these nodules do represent a pediatric thyroid cancer, making careful evaluation key to detection.

The American College of Radiology Thyroid Imaging, Reporting, and Data System (ACR TI-RADS) is a validated and widely used tool for the management of thyroid nodules in adults. Specifically, it relies on standardized ultrasound criteria to help guide clinical decisions about whether thyroid nodules should be biopsied. Although it was developed for adults, ACR TI-RADS has been increasingly used to evaluate thyroid nodules in children, despite the fact that its efficacy hasn’t been validated in a pediatric population.

Now, findings of a new retrospective study by researchers in the Thyroid Center at Boston Children’s Hospital and Brigham and Women’s Hospital indicate that ACR TI-RADS may fail to detect a significant number of thyroid cancers in a pediatric population.

“Because thyroid nodules and cancer are so much more common in adults than in children, historically we have had to manage children with these conditions as best we can using the evidence and tools developed in adults,” says Ari Wassner, MD, the Center’s medical director.  “However, since we know that thyroid cancer behaves differently in children and adults, it is important to make sure that the clinical tools used for diagnosis and treatment in adults are appropriate for children before they are applied broadly to the pediatric population.”

One-fifth of cancers missed

To assess the effectiveness of ACR TI-RADS in evaluating thyroid nodules in children, the team analyzed data from 314 children and adolescents who underwent fine-needle aspiration of a thyroid nodule between 2004 and 2017. They applied ACR TI-RADS criteria to each nodule and then assessed whether the use of ACR TI-RADS would have changed the way the nodule was managed. For example, they determined whether using ACR TI-RADS would have altered whether a biopsy was performed or would have affected a diagnosis of thyroid cancer. 

Of the 404 thyroid nodules scored, 77 were malignant. Yet, using the ACR TI-RADS criteria would have failed to diagnose 17 — or 22 percent — of the cancers in this patient cohort at their initial evaluation. Because this approach failed to identify more than one-fifth of malignant thyroid nodules, the study’s authors concluded that the current ACR TI-RADS criteria are inadequate for evaluating thyroid nodules in children. The authors describe minor modifications that could improve the performance of ACR TI-RADS in the pediatric population. The study was published in the December 10, 2019, issue of Radiology.

“This study is a good example of how some important clinical tools for evaluating thyroid nodules and cancer in adults—like systems for classifying ultrasound findings or cytological abnormalities—require validation, and potentially modification, to work optimally in children,” says Wassner.  “We hope that this and future studies will improve our ability to provide the best possible care for children with thyroid nodules and cancer.”

Learn about the Thyroid Center.