Ultrasound-guided radiofrequency ablation for low-risk papillary thyroid microcarcinoma: A non-surgical organ-preserving alternative

Abstract

Background: Papillary thyroid microcarcinoma (PTMC, < 1 cm) without lymph node metastasis or extrathyroidal extension (cT1aN0M0) is increasingly detected in young adults. European Thyroid Association guidelines endorse image-guided Radiofrequency Ablation (RFA) as an effective, organ-preserving alternative to surgery.

Case summary: A 25-year-old euthyroid, non-diabetic male presented with mild neck pain, malaise, and sound-induced anxiety. Neck ultrasonography revealed a right EU-TIRADS 5 thyroid nodule (0.79 × 0.52 × 0.60 cm, volume 0.13 mL). FNAC confirmed PTMC, while contrast-enhanced CT ruled out lymphadenopathy and metastasis. To avoid thyroidectomy, ultrasound-guided RFA was performed under local anesthesia with fluid hydrodissection. Using a trans-isthmic and lateral approach and a 5 mm active-tip electrode, RFA was delivered at 20W for 3 minutes. Immediate post-ablation ultrasound confirmed complete hyperechoic avascular necrosis (0.55 x 1.2 x 0.70 cm, volume 0.24 mL) with a safety margin. The procedure was uneventful, without vocal cord paresis, hematoma, or voice changes. At 1-month follow-up, ultrasound demonstrated a completely avascular, mixed-echogenic ablation zone (0.60 x 1.10 x 0.68 cm, volume 0.23 mL). Persistent absence of vascularity on Doppler confirmed complete thermal necrosis, with transient volume expansion attributable to post-ablation edema and safety margins.

Conclusion: Ultrasound-guided RFA is a safe, effective, and organ-preserving alternative to surgery for low-risk PTMC, achieving immediate technical success and full functional preservation. Structured follow-up at 3, 6, and 12 months (and onwards) remains essential to monitor progressive volume shrinkage, confirm complete radiological disappearance, and ensure long-term oncologic efficacy.

[J Assoc Clin Endocrinol Diabetol Bangladesh, 2026;5(Suppl 1): S59]