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

Abstract

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.

Keywords: Active surveillance; Guideline; Korean; Papillary thyroid microcarcinoma; Thyroid neoplasms.

Fig. 1.

Ultrasound-based appropriateness criteria for active surveillance in papillary thyroid microcarcinoma. Subcapsular tumors are defined as lesions that abut either the anterior or posterior thyroid capsule. A tumor in contact with the anterior capsule (yellow line) is categorized as an anterior subcapsular tumor, whereas tumors that touch the posteromedial capsule (red line) or the posterolateral capsule (blue line) are classified as posteromedial and posterolateral subcapsular tumors, respectively. Modified from Lee et al. [32]. TEG, tracheoesophageal groove.

Fig. 2.

Algorithm for follow-up during active surveillance (AS). US, ultrasound; ETE, extrathyroidal extension; LN, lymph node.