Efficacy analysis of ultrasound-guided radiofrequency ablation for papillary thyroid carcinoma adjacent to the thyroid capsule

LI Chenhui; ZHANG Ruirui; DING Siyue; SUN Mengjin; NIU Jinling; LI Qian

doi:10.19300/j.2025.L22104

Abstract：Objective To investigate the efficacy and safety of ultrasound-guided radiofrequency ablation(US-RFA)in the treatment of papillary thyroid carcinoma(PTC)adjacent to the thyroid capsule.Methods A retrospective analysis was conducted on 126 patients with PTC who underwent US-RFA.Among them,47 cases had PTC adjacent to the thyroid capsule,and 79 cases had non-capsule-adjacent PTC.All patients underwent fine-needle aspiration biopsy(FNAB)before the procedure to confirm pathological diagnosis,and patients with cervical lymph node or distant metastasis were excluded.During the ablation,techniques such as expanded ablation and hydrodissection were applied.Contrast-enhanced ultrasound was performed immediately after the procedure to assess the ablation range and ensure complete ablation.Follow-ups were conducted at 1,3,6,and 12 months postoperatively to monitor changes in the maximum diameter and volume of the ablation site,as well as the occurrence of recurrence,cervical lymph node metastasis,or distant metastasis.Differences between groups were analyzed using t-test,Mann-Whitney U test,and Chi-square test.Results All 126 cases of PTC achieved complete ablation.There were no statistically significant differences in gender,preoperative tumor maximum diameter,preoperative tumor volume,and BRAFV600E between the two groups(all P＞0.05).However,the mean age in the capsule-adjacent group was significantly higher than in the non-capsule-adjacent group(P＜0.05).The rate of hydrodissection use in the capsule-adjacent group(100%)was higher than that in the non-capsule-adjacent group(35.4%).During the follow-up period,there were no significant differencesbetween the two groups in terms of volume reduction rate of the ablation zone and complete tumor disappearance rates at 3 and 12 months postoperatively(all P＞0.05).However,at 6 months after the operation,the complete disappearance rate of the tumor was higher in the non-capsule-adjacent group than in the capsule-adjacent group(P＜0.05).During the follow-up period,no local tumor recurrence or lymph node metastasis was observed in either group.Conclusion US-RFA is a safe and effective treatment for PTC adjacent to the thyroid capsule without lymph node or distant metastasis.