Fine Needle Aspiration Versus the CytoCore® Motorized Rotating Needle Device for Thyroid Nodule Biopsies: A Retrospective Cohort Study

Background While ultrasound guided fine needle aspiration (US-FNA) is commonly used to biopsy suspicious thyroid nodules, its use is associated with a high rate of nondiagnostic and indeterminate samples. The objective of this study was to compare the diagnostic performance of a new motorized FNA device (CytoCore®, Praxis Medical) to a historical cohort of patients biopsied using US-FNA within the same health system and literature controls. Materials and Methods Data from 120 patients with suspicious thyroid nodules undergoing thyroid biopsy with a motorized FNA device between March 2022 and August 2023 was retrospectively analyzed. Patient demographics, lesion characteristics, number of passes required, Bethesda category, and cellularity scores were compared to a historical control cohort of 100 patients who underwent US-FNA between March 2019 and March 2020. All patients underwent the procedure within the same health system. Nondiagnostic and indeterminate samples rates for the motorized FNA device were separately compared to literature controls. Results A significantly reduced median number of passes were required with the motorized FNA device compared to US-FNA ( z = 8.235, p < .001). Adequate samples were obtained after the first pass for 58% of nodules biopsied with motorized FNA device compared to only 11% with US-FNA. The cumulative percentage of adequate samples increased to 98% after two passes for the motorized FNA group versus only 58% for the US-FNA group. Eleven percent of subjects in the US-FNA required 5 passes to obtain an adequate sample. The mean cellularity score was also greater for the motorized FNA group (3.5 ± 0.5 vs. 2.0 ± 0.6; z = 5.201, p < .001). Compared to published rates, the motorized had a lower nondiagnostic rate (2.0% vs. 10% to 15%) and lower indeterminate rate (8.3% vs. 20%; p=0.05) compared to the use of FNA. Conclusion The motorized FNA device requires less passes to obtain an adequate biopsy than US-FNA, thus decreasing procedure length, tissue trauma, and damage to the specimen damage. Its use is also associated with obtaining samples with a higher cellularity and lower nondiagnostic and indeterminate sample rates.