Comparison of two puncture techniques for fine-needle capillary biopsy in thyroid nodules: a randomized controlled trial.

To-and-fro puncture and to-and-fro whirling puncture are two common specimen acquisition methods of thyroid fine-needle capillary (FNC) biopsy. While both techniques are widely used, a direct comparison of their outcomes has been lacking. This prospective study enrolled 110 patients with 138 thyroid nodules. Each nodule underwent four punctures: two using the to-and-fro technique and two using the to-and-fro whirling technique. The primary outcome was specimen adequacy, while secondary outcomes included malignancy diagnosis rate, sensitivity, diagnostic accuracy, and procedure time. No significant difference was found in specimen adequacy between the two techniques (90.58% vs. 89.86%, p = 0.839). However, the to-and-fro technique demonstrated superior performance in terms of malignancy diagnosis rate (31.88% vs. 20.29%, p = 0.028), sensitivity (100.00% vs. 81.82%, p = 0.006), and diagnostic accuracy (97.78% vs. 83.33%, p = 0.041). Additionally, the to-and-fro technique required less procedure time (18.38 ± 8.34 seconds vs. 20.84 ± 10.54 seconds, p < 0.001). In conclusion, both the to-and-fro puncture technique FNC and the to-and-fro whirling puncture technique FNC demonstrated comparable specimen adequacy, and both can achieve good specimen adequacy. The to-and-fro puncture technique shows potential advantages in terms of operation time, reduction of the risk of missed diagnosis of malignant tumors, sensitivity, and diagnostic accuracy. Trial registration: Chinese Clinical Trial Registry, ChiCTR2400080882. Registered 14 February 2024.