Incidental thyroid nodules in neuro CT: Who dropped the ball? Impact on CT reports on management of patients

From the 2019 HVPAA National Conference

Dr. Elizabeth Ryals (University of Utah), Dr. Zachary Berg (University of Utah), Mrs. Anna Darelli-Anderson (University of Utah), Dr. Lubdha Shah (University of Utah), Dr. Yoshimi Anzai (University of Utah)

Background

Overdiagnosis of small indolent TC discovered during CT or MR, so-called incidental thyroid nodules (ITN), is reported to contribute to increased incidence of thyroid cancer (TC). Thyroid Ultrasound (US) and biopsy lead to the detection of early-stage TC that may not lead to patients health benefits with a small risk of complications.

Objectives of this study are to determine the incidence of ITN, reporting variability, compliance with the ACR (American College of Radiology) and ATA (American Thyroid Association) guidelines, factors affecting recommendation of the further US workup, and the compliance to US recommendation,

Materials and Methods

Among 11530 neuro CT examinations covering the neck from 1/1/2016 to 12/31/2016, natural language processing (NLP) with a search word “thyroid nodule (TN)” was applied. Imaging reports were reviewed to identify the size of TN, whether TNs were reported in the body of reports or impression (summary), and recommendation as to further US workup. We reviewed patient demographics, the location of the service, whether or not TN met the ACR and ATA guidelines for the US, and if patients underwent those recommended US.

Results

Among 196 neuro CT reports contain a description of ITN (1.7%), the size of TNs was reported in 158 reports. TN was reported in the Impression in 90 cases, of which 49 met the ACR guidelines whereas 72 met the ATA guidelines for US workups. US workup was recommended in 57 out of 90 cases. Ten patients lost follow-ups. Among 47 cases US was explicitly recommended, only 8 underwent US of the thyroid (17%), and 4 underwent FNA subsequently. TN was described in the body of reports in 68 cases, 9 met the ACR and 24 met the ATA guidelines for US workups, though US was recommended in only one patient. The logistic regression revealed that the most significant factor for predicting US recommendation was the size of TN (OR: 1.2, p<0.001) followed by age (OR 0.98, p=0.08). The compliance with the ACR and ATA guidelines was 72.2% and 68.4%. ATA guidelines led to a higher frequency of US recommendation by 67%.

Conclusion

ITN was reported only in 1.7% of neuro CT examinations. Radiologists report TN under Impression and recommend US workup when TN is larger and younger patients. Despite the recommendation, only 17% of patients underwent thyroid US. The future study focuses on the possible reasons for not following the US recommendation.

Clinical Implications

Radiologists describe ITN in their reports according to ACR or ATA guidelines. However, only 17% of patients in our series received thyroid US as recommended in the Impression. Although patients might have received US outside of our health system, it raises a concern that ITN is generally ignored, possibly due to a false sense of assurance that ITN is indolent or providers do not remember all of the recommendations. Effective reminder incorporated into the EHRs and clinical workflow is desired.