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

Abstract

Introduction: Recently, an FDA cleared motorized fine-needle aspiration device (CytoCore®, Praxis Medical) has become available which is designed to reduce sample variability by enabling more consistent sampling due to the rotational drilling action of the device in combination with the standard in and out motion used to access the thyroid nodule with a needle. The rotation of the needle permits the ability to collect a higher quantity of intact cellular material, which is optimal for determining adequacy and, ultimately, for making a diagnosis. The present study compares the diagnostic performance of a motorized fine needle aspiration (FNA) device to a historical cohort of patients biopsied using ultrasound-guided fine needle aspiration (US-FNA). Methods: Data from 120 patients with thyroid nodules biopsied using a motorized FNA device was retrospectively analyzed. Patient demographics, lesion characteristics, number of passes, Bethesda category, and cellularity scores were compared to a historical control cohort of 100 patients who underwent US-FNA. Nondiagnostic and indeterminate samples rates for motorized FNA were separately compared to literature controls. Results: A significantly reduced median number of passes were required with motorized FNA compared to US-FNA (1.48 ± 0.62 vs. 2.64 ± 1.63, p < 0.001). Adequate samples were obtained after the first pass for 58% of biopsies with motorized FNA compared to 11% with US-FNA. The cumulative percentage of adequate samples increased to 98% after two passes for motorized FNA versus 58% for the US-FNA group. The mean cellularity score was also significantly greater for motorized FNA (3.42 ± 0.63 vs. 1.9 ± 0.59; p < 0.001). A determinant diagnosis was possible for a greater number of samples in the motorized FNA group compared to the control group (91.6% vs. 78%; p = 0.05). The motorized FNA also had a lower nondiagnostic rate compared to US-FNA (2.0% vs. 10%) and a lower indeterminate rate compared to published rates associated with the use of FNA (8.3% vs. 20.0%; p = 0.05). Conclusion: The motorized FNA device required less passes to obtain an adequate biopsy than US-FNA. Its use is also associated with obtaining samples with a higher cellularity and lower nondiagnostic and indeterminate sample rates.