Effect of fine needle aspiration biopsy on change in thyroid nodule elasticity.

Aims: This study aimed to investigate changes in the stiffness of thyroid nodules following fine needle aspiration biopsy (FNAB), using shear wave elastography (SWE), a non-invasive imaging technique utilized in thyroid nodule evaluation.

Material and methods: A total of 82 patients scheduled to undergo FNAB for the first time were included. Ultrasound and SWE examinations were performed before the procedure and again 8 to 10 weeks after FNAB. Nodule stiffness was measured in kilopascals (kPa) during both evaluations, and changes in elasticity were assessed.

Results: The mean SWE stiffness of the nodules significantly decreased from 21.80 ± 11.43 kPa before FNAB to 17.83 ± 9.98 kPa after FNAB (p = 0.001). Smoking status and serum free T3 levels were significantly associated with changes in SWE stiffness (p < 0.05). However, no significant difference was observed between TIRADS 3 and TIRADS 4 categories regarding the change in stiffness (p = 0.223).

Conclusion: This study demonstrates a significant reduction in thyroid nodule stiffness after FNAB as measured by SWE. These post-biopsy changes may lead to potential misinterpretations in subsequent elastographic evaluations, possibly affecting diagnostic accuracy and clinical decision-making.