To explore the curative effect and influencing factors of percutaneous radiofrequency ablation (PRFA) for benign thyroid nodules in order to improve the effect of thyroid benign nodule ablation treatment.

The study included 482 benign thyroid nodules. The largest diameter of benign thyroid nodules ranges from 0.7 to 9.2 cm. Two hundred and fifty-eight nodules were solid nodules, 224 nodules were cystic-solid nodules, and 96 thyroid nodules combined with the background of Hashimoto′s thyroiditis. The patients of this study included 356 females and 126 males, the ages of the study population ranged from 14 to 82 years old. In order to observe the local pain, swelling, skin infection, hoarseness and other complications of the thyroid nodules with PRFA, we conducted conventional ultrasound and contrast-enhanced ultrasound immediately and followed up in 1, 3, 6, 12, 18 and 24 months after the treatment. Besides, the nodule volume reduction ratio was calculated , and the effects of gender, age, nodule size, cystic proportion, and the background of Hashimoto′s thyroiditis on the treatment were analyzed.

The volume of benign thyroid nodules after the PRFA treatment was significantly reduced after 1, 3, 6, 12, 18, 24 months, and their nodule volume reduction ratio (VRR) was (51.2±5.7)% (1 months), (69.7±4.3)% (3 months), (84.6±3.7)% (6 months), (89.3±2.9)% (12 months), (93.7±1.6)% (18 months) and (94.9±1.4)% (24 months), respectively. The thyroid nodules were divided into 3 groups according to the cystic portion, significant differences were found in the volume reduction rate at 1, 3, 6, 12, 18 and 24 months after PRFA (F=66.858, 69.101, 19.410, 49.559, 146.653 and 309.950 respectively, all P<0.001), the more cystic portion was, the faster the lesion shrinked. The nodules with the cystic portion<20% were grouped according to the maximum diameter (≤3 cm />3 cm), and the background of Hashimoto′s disease; and significant differences were found in the volume reduction rate at 1, 3, 6, 12, 18 and 24 months after PRFA (the t values for different size groups were 9.710, 8.925, 9.899, 12.734, 17.226 and 42.580, respectively, the t values for whether there is a background of Hashimoto′s disease were 66.858, 69.101, 19.410, 49.559, 146.653, 309.950, respectively, all P<0.001). The VRR of nodules of which the maximum diameter≤3 cm, or without Hashimoto′s thyroiditis was larger after radiofrequency ablation. The nodules of which the maximum diameter≤3 cm and with the cystic portion <20% were grouped according to different genders (male or female) and different ages (≤40 or>40 years old), and the mean VRR of the nodules between different gender and age groups are not significantly different (P>0.05).

Ultrasound guided PRFA is a safe and effective minimally invasive therapy for benign thyroid nodules.