Comparative utility of fine-needle aspiration biopsy vs. ultrasound in detecting residual disease after radiofrequency ablation for papillary thyroid microcarcinoma: a retrospective case series

Papillary thyroid microcarcinoma (PTMC) is typically indolent and associated with excellent disease-specific outcomes; however, its optimal management remains debated, with options ranging from active surveillance to surgical intervention. Radiofrequency ablation (RFA) has emerged as a minimally invasive alternative for selected low-risk PTMC patients, achieving substantial tumor volume reduction while preserving thyroid function. Post-RFA surveillance relies primarily on ultrasound imaging, which may be limited in identifying residual viable disease. The role of fine-needle aspiration biopsy (FNAB) in post-ablation follow-up remains insufficiently characterized.