Ultrasound Imaging Criteria and Protocols for Active Surveillance of Low-Risk Thyroid Cancer: A Review of International Consensus Guidelines

• Published in: Endocrinology and metabolism (Seoul) Vol. 40; no. 2; pp. 185 - 194
• Main Author: Lee, Ji Ye
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Endocrine Society 01.04.2025; 대한내분비학회
• Subjects: active surveillance; Carcinoma, Papillary - diagnostic imaging; Carcinoma, Papillary - pathology; computed tomography; Consensus; guideline; Humans; practice guideline; Practice Guidelines as Topic - standards; Review; thyroid cancer, papillary; Thyroid Neoplasms - diagnostic imaging; Thyroid Neoplasms - pathology; Ultrasonography - methods; Ultrasonography - standards; ultrasound; Watchful Waiting - methods; Watchful Waiting - standards; 내과학; Practice guideline; Guideline; Active surveillance; Computed tomography; Thyroid cancer, papillary; Ultrasound
• ISSN: 2093-596X; 2093-5978; 2093-5978
• DOI: 10.3803/EnM.2024.2319

Given the indolent nature and favorable outcomes of papillary thyroid microcarcinoma (PTMC), active surveillance (AS) has been adopted as an alternative management option to immediate surgery. However, the meticulous selection of patients based on individual and tumor-specific characteristics, as well as ultrasound (US) findings, is crucial in AS. Regular US monitoring is performed during AS to detect indicators of tumor progression, such as growth, the emergence of new US features suggestive of gross extrathyroidal extension, and lymph node metastasis. Thus, imaging-based evaluations play a pivotal role in guiding the decision to continue AS or proceed with surgical intervention. This review introduces the Korean Society of Thyroid Radiology (KSThR) guideline for the standardized US imaging of patients with low-risk PTMC under AS, which provide practical recommendations for tumor assessment during the initiation and follow-up phases of AS. This review compared the key features of the KSThR guideline with those of major international guidelines and identified the similarities and differences in imaging methodologies and follow-up strategies. The primary objective of this review is to support the broader implementation of AS and improve outcomes for patients with low-risk PTMC by emphasizing imaging protocols.