Comparison of ACR-TIRADS to the ATA Guidelines for Thyroid Nodules: A Neck to Neck Comparison

Authors

  • Judy K Qiang Department of Medicine, Division of Endocrinology and Metabolism, University of Toronto; Toronto, Ontario, Canada
  • Carrie Betel 2Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
  • Kalesha Hack Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
  • Zeina Ghorab Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
  • Julie Gilmour Department of Medicine, Division of Endocrinology and Metabolism, University of Toronto; Toronto, Ontario, Canada
  • Manijeh Mohammadi Department of Medicine, Division of Endocrinology and Metabolism, McMaster University, Hamilton, Ontario, Canada
  • Kirsteen Burton Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
  • Ilana Halperin Department of Medicine, Division of Endocrinology and Metabolism, University of Toronto; Toronto, Ontario, Canada

Keywords:

Thyroid nodules, cancer risk, ultrasound, ACR-TIRADS, ATA

Abstract

Introduction: The goal of this study was to compare the performance characteristics of the American
College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS) and the American
Thyroid Association (ATA) systems in identifying malignant thyroid nodules.
Methods: In a retrospective chart review, ultrasound images of all thyroid nodules biopsied in 2014-
2015 at a Canadian academic centre were reviewed by two radiologists. The ultrasound characteristics of
thyroid nodules were compared with cytologic or pathologic results to determine the positive predictive
value (PPV), negative predictive value (NPV), sensitivity and specificity for TIRADS and ATA in
predicting cancer risk. Clinical course of nodules not requiring follow up or intervention according to
ACR-TIRADS was described. Vascularity was added to ACR-TIRADS to determine whether sensitivity
of TIRADS improves.
Results: A total of 417 thyroid nodules were reviewed, 82% were benign (Bethesda II). The sensitivity,
specificity, PPV, and NPV were 97%, 11%, 9%, 98%, and 70%, 29%, 18%, and 81% for ATA and
TIRADS, respectively. Of the 10 nodules that did not need ultrasound follow up based on TIRADS
criteria, 2 were malignant, the rest were FLUS. If vascularity was added to TIRADS (TIRADS-Vasc),
the number of malignant cases missed could have been reduced by 43% (from 7 to 4 cases).
Conclusions: TIRADS is more specific but less sensitive than ATA, and misses a small number of
malignant nodules. Clinicians need to use their judgement to decide which nodules require biopsy as
some malignant cases will be missed using TIRADS alone.

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Published

2022-01-02

Issue

Vol. 1 No. 1: Current Issue

Section

Articles