Ioakim S, Syed AA, Zavros G, Picolos M, Persani L, Kyriacou A. Real-world application of ATA Guidelines in over 600 aspirated thyroid nodules: is it time to change the size cut-offs for FNA?
Eur Thyroid J 2022;
11:e220163. [PMID:
36215117 PMCID:
PMC9641794 DOI:
10.1530/etj-22-0163]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 11/08/2022] Open
Abstract
Background
The 2015 American Thyroid Association (ATA) Guidelines recommend the following size cut-offs based on sonographic appearances for subjecting nodules to fine-needle aspiration (FNA) biopsy: low risk: 15 mm and intermediate risk and high risk: 10 mm.
Objective
We conducted a 'real-world' study evaluating the diagnostic performance of the ATA cut-offs against increased thresholds, in the interest of safely limiting FNAs.
Methods
We performed a retrospective analysis of prospectively collected data on 604 nodules which were sonographically risk-stratified as per the ATA Guidelines and subsequently subjected to ultrasound-guided FNA. Nodules were cytologically stratified into 'benign' (Bethesda class 2) and 'non-benign' (Bethesda classes 3-6). We obtained the negative predictive value (NPV), accuracy, FNAs that could be spared, missed 'non-benign' cytologies and missed carcinomas on histology, according to the ATA cut-offs compared to higher cut-offs.
Results
In low-risk nodules, the high performance of NPV (≈91%) is unaffected by increasing the cut-off to 25 mm, and accuracy improves by 39.4%; 46.8% of FNAs could be spared at the expense of few missed B3-B6 cytologies (7.9%) and no missed carcinomas. In intermediate-risk nodules, a 15 mm cut-off increases the NPV by 11.3% and accuracy by 40.7%. The spared FNAs approach 50%, while B3-B6 cytologies are minimal, with no missed carcinomas. In high-risk nodules, low NPV (<35%) and accuracy (<46%) were obtained regardless of cut-off. Moreover, the spared FNAs achieved at higher cut-offs involved numerous missed 'non-benign' cytologies and carcinomas.
Conclusion
It would be clinically safe to increase the ATA cut-offs for FNA in low-risk nodules to 25 mm and in intermediate-risk nodules to 15 mm.
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