Evaluation of contrast-enhanced ultrasound-guided fine needle aspiration biopsy in thyroid nodule diagnosis: a study from two tertiary referral centers.

PURPOSE: This study aimed to compare the final definitive diagnosis (FDD) rate and accuracy of contrast-enhanced ultrasound (CEUS)-guided fine-needle aspiration biopsy (FNAB) with conventional US-guided FNAB. METHODS: A two-center study was conducted to compare the diagnostic performance of FNAB with or without CEUS guiding between April 2014 and April 2024. In center 1, 1,074 patients with thyroid nodules who had undergone FNAB were retrospectively evaluated. Among them, 526 nodules were guided by CEUS, and 548 nodules were guided by conventional US. In center 2, 382 patients were included for a prospective study; 91 nodules received CEUS-guided FNAB and 291 nodules received conventional US-guided FNAB. The rate of non-diagnosis and indeterminate results of the two kinds of FNAB were calculated, and the FDD rate and diagnostic accuracy were compared in the two centers. RESULTS: In the retrospective study, there were significant differences between FNABs guided by CEUS and those guided by conventional US in the non-diagnostic rates (0.4% vs. 6.2%, P < 0.001) and indeterminate rates (4.4% vs. 11.1%, P < 0.001); the rates of FDD were 93.3% vs. 77.9%, (P < 0.001), and the accuracy was 99.8% vs. 98.1 (P = 0.015). In the prospective study, the non-diagnostic rates were 8.8% vs. 11.0% in the two groups (P = 0.695), and the indeterminate rates were 1.1% vs. 9.6% (P < 0.001); the rate of FDD was 80.2% vs. 69.7%, (P = 0.018), and the accuracy was 100% vs. 94.4, (P = 0.039). CONCLUSION: CEUS-guided FNAB appears to have additional benefits in FDD and accuracy compared with conventional US-guided FNAB. CLINICAL SIGNIFICANCE: CEUS-guided FNAB can reduce repeat FNABs and diagnostic surgeries.