2025 Korean Thyroid Association Clinical Management Guideline on Active Surveillance for Low-Risk Papillary Thyroid Carcinoma.

The increasing detection of papillary thyroid microcarcinoma (PTMC) has raised concerns regarding overtreatment. For low-risk PTMC, either immediate surgery or active surveillance (AS) can be considered. To facilitate the implementation of AS, the Korean Thyroid Association convened a multidisciplinary panel and developed the first Korean guideline. AS is recommended for adults with pathologically confirmed Bethesda V-VI PTMC who have no clinical evidence of lymph node or distant metastasis, gross extrathyroidal extension, invasion of the trachea or recurrent laryngeal nerve, or aggressive histology. A baseline assessment requires high-resolution neck ultrasound performed by experienced operators to exclude extrathyroidal extension, tracheal or recurrent laryngeal nerve invasion, and lymph node metastasis; contrast-enhanced neck computed tomography is optional. Patient characteristics, including age, comorbidities, and the capacity for long-term follow-up, should be thoroughly assessed. Shared decision-making should carefully weigh the benefits and risks of surgery versus AS, considering expected oncologic outcomes, potential complications, quality of life, anxiety, medical costs, and patient preference. Follow-up involves neck ultrasound and thyroid function tests every 6 months for 2 years and annually thereafter. Disease progression, defined as significant tumor growth or newly detected nodal or distant metastasis, warrants surgery. Despite remaining uncertainties, this guideline provides a structured framework to ensure oncologic safety and supports patient-centered AS.