Postoperative Surveillance in Differentiated Thyroid Cancer: Response-Adapted De-Escalation in the 2025 American Thyroid Association and 2026 Korean Thyroid Association Guidelines

Postoperative surveillance for differentiated thyroid cancer (DTC) is shifting from routine, uniformly intensive follow-up toward risk-adapted, response-based care.Because most patients with DTC have an excellent prognosis, surveillance should not rely on indefinite testing to maximize recurrence detection.Rather, it should prioritize detection of clinically meaningful recurrence while reducing unnecessary biochemical testing, imaging, and prolonged thyroid-stimulating hormone (TSH) suppression [1,2].Although initial clinicopathological risk stratification remains essential, recurrence risk should be recalibrated over time according to surgical extent, radioactive iodine (RAI) use, serum thyroglobulin (Tg) level, anti-thyroglobulin antibody (TgAb) status, imaging findings, and treatment response [3,4].The 2026 Korean Thyroid Association (KTA) and 2025 American Thyroid Association (ATA) guidelines share this overall direction [1,2], but they differ in several clinically important respects: the timing of early postoperative assessment, Tg interpretation after treatment without RAI or after lobectomy, and the extent of long-term surveillance de-escalation (Table 1).