Oral Presentation ESA-SRB-APEG-NZSE 2022

ACR TI-RADS has limited utility in a real-world setting: correlation of results and patient outcomes in a cohort presenting for thyroid ultrasonography (#166)

Tom Wilkinson 1 , Thomas Cawood 1 , Anthony Lim 1 , Penny Hunt 1 , David Roche 2
  1. Canterbury District Health Board, Christchurch, NZ, New Zealand
  2. Canterbury Southern Community Laboratories, Christchurch, New Zealand

Aims:  The American College of Radiology Thyroid Image Reporting and Data System (ACR TI-RADS) was developed to predict malignancy risk in thyroid nodules using ultrasound features, to identify patients who would most benefit from investigation with fine needle aspiration (FNA)(1).  TI-RADS was derived from a pre-existing database of FNA results, raising uncertainty about applicability to unselected patients presenting with a thyroid nodule in whom the risk of malignancy may be lower.  We assessed malignancy rates in a cohort of patients presenting for ultrasound and the impact of routine reporting of TI-RADS on patient outcomes.

Methods:  Records for all patients presenting for thyroid ultrasonography in Canterbury, New Zealand were retrospectively reviewed across two intervals: 1/1/2017-30/6/2018 (prior to implementation of TI-RADS reporting) and 1/1/2020-30/6/2021 (after implementation of TI-RADS reporting).  Malignancy rates were calculated for nodules >10mm with a definitive FNA or histology result.

Results:  1210 nodules were identified in 582 patients prior to implementation of TI-RADS.  1253 nodules were identified in 625 patients after implementation of TI-RADS.  After implementation of TI-RADS, fewer patients proceeded to FNA (49% vs. 60%, p<0.01) or surgery (14% vs. 18%, p<0.05), with no difference in cancer diagnoses (3% vs. 4%, NS), however FNA procedures would not have decreased if ACR TI-RADS recommendations were strictly followed.  TI-RADS category was associated with malignancy rate (0% in TR1 and TR2, 3% in TR3, 5% in TR4, and 12% in TR5).  Notably, 63% of nodules were graded TR3 or TR4, where rate of malignancy did not meaningfully differ from baseline.

Conclusion:  TI-RADS category is associated with malignancy rate in patients presenting for thyroid ultrasound, however is non-discriminatory in the majority of nodules.  Nodules classified as “highly suspicious” have only a modestly increased malignancy rate.  Routine implementation of ACR TI-RADS appears to alter clinical decision making for only a minority of patients.

  1. Tessler FN, Middleton WD, Grant EG, Hoang JK, Berland LL, Teefey SA, et al. ACR thyroid imaging, reporting and data system (TI-RADS): white paper of the ACR TI-RADS committee. Journal of the American College of Radiology. 2017;14(5):587-595.