FRI470 The Impact Of COVID-19 Lockdown On Thyroid Fine Needle Aspiration Volume And Malignancy Rate
Authors: Larkin Kelsey , Li Jiazhen , Brandler Tamar C , Ling Fan , Greenberg Patricia , Cohen David A 
Published: October 2023

Disclosure: K. Larkin: None. J. Li: None. T.C. Brandler: None. F. Ling: None. D.A. Cohen: None.

Background: During the COVID-19 pandemic many elective procedures were postponed, including thyroid nodule fine needle aspiration biopsies (FNABs). These delays may have led to a lag in diagnosis of thyroid cancer. Our study aims to determine whether there were fewer FNABs performed during and immediately after lockdown, with subsequent higher than baseline volume in the 6–12-months after, before returning to baseline. We hypothesized that due to a stringent threshold for biopsy referral, malignancy rates would be higher during and immediately after lockdown before decreasing to lower than baseline. Our study’s findings may aid in future determination of procedure prioritization during crises. Methods: This single-center retrospective chart review was performed at the Endocrinology Clinic at Robert Wood Johnson Hospital at Rutgers University. The study included over 1800 samples collected from 04/19-03/21 in patients age &gt; 18 years. Patients with history of thyroid cancer were excluded. We assessed raw number and rate of malignancy diagnosed in 60-day periods defined as “pre-lockdown,” “during lockdown,” and “post-lockdown.” We defined malignant FNAB cytology, based on the Bethesda scoring system, as suspicious or positive for malignancy (score of V or VI). Summary statistics were calculated using means or percentages as appropriate. Results: 1862 thyroid nodule FNABs were analyzed. 1046 FNABs were performed in pre-lockdown (4/1/2019-3/10/2020), for an average of 182.44 FNABs per 60-day period. 70 FNABs were performed during lockdown (3/10/2020-6/2/2020), for an average of 50 FNABs per 60-day period. This represents a 72.59% decline in FNAB volume. During post-lockdown, the average number of FNABs performed were 150, 130, 157, 132.78 and 185.17 per 60-day time period. During pre-lockdown, 48 FNABs met our criteria for malignancy, with a true positivity rate of 4.58%. During lockdown, 4 FNABs met criteria, for a true positivity rate of 5.71%. This represents an increase in positivity of 25%. During post-lockdown, true positivity rates were 3.4%, 3.8%, 3.8%, 5.2%, and 5.7%. Discussion and Conclusion: During the COVID-19 lockdown, volume of thyroid nodule FNABs decreased by 72.59% and nodules were 25% more likely to be positive. During post-lockdown, the number of FNABs began to return to baseline. Malignancy rates initially declined and then surpassed pre-lockdown rates. We speculate that given the decrease in number of FNABs performed during lockdown combined with the increased rate of malignancy, thyroid nodules determined to be clinically significant were prioritized. With that, it is likely that malignant nodules were missed, or diagnosis delayed, potentially accounting for higher rates in later post-lockdown periods. This information can aid future situations of crisis, as a more organized and informed approach can give patients the opportunity to seek elective procedures.

Presentation: Friday, June 16, 2023