Analysis of the Factor which Affect to Acquisiton Rate of Ultrasound-Guided Fine Needle Aspiration of Thyroid Nodules

ABSTRACT

PURPOSE: The purpose of this study is to evaluate the acquisition rate of adequate specimens in the ultrasoundguided percutaneous needle aspiration biopsy (US-PCNB) of thyroid nodules and to find the factors influencing the acquisition rate. MATERIALS AND METHODS: We conducted a prospective study in 132 patients who had a total of 215 nodules. Aspiration biopsy was performed with 21-gauge fine needles for 111 nodules (62 patients) and with 20-gauge cutting needles for 104 nodules (70 patients). We calculated the overall acquisition rate of adequate specimens of US-PCNB and compared the acquisition rates according to the kind of needle, and the size, nature and palpability of the nodules. RESULTS: The total acquisition rate of adequate specimens was 87.4%. There was no difference in the acquisition rate between the 20-gauge cutting needle and the 21-gauge needle. The acquisition rate of the solid nodules (90.2%) was higher than that of the cystic nodules (78.8%). However, the size and palpability of the nodules did not significantly affect the acquisition rate of the specimens. CONCLUSION: The acquisition rate of adequate specimens in the US-PCNB of thyroid nodules was high. The acquisition rate of the solid nodules was higher than that of the cystic nodules. However, there was no statistically significant difference in the acquisition rate according to the kind of needle, or the size and palpability of the nodules.