Intermediate‐Risk Papillary Thyroid Cancer: Not Everyone Needs Radioactive Iodine

Introduction Intermediate‐risk papillary thyroid carcinoma (PTC) accounts for 40%–60% of newly diagnosed PTC and comprises a heterogeneous group with variable recurrence risk. The benefit of postoperative radioactive iodine (RAI) remains uncertain. Objectives To describe features, response‐to‐therapy outcomes, and ATA 2025 recurrence‐risk redistribution in patients with ATA 2015 intermediate‐risk PTC managed without adjuvant RAI. Design Retrospective cohort study. Methods Adults (≥ 18 years) with ATA 2015 intermediate‐risk PTC treated with total thyroidectomy (TT) or thyroid lobectomy (TL), with/without lymph node dissection, and followed for ≥ 1 year were included. Omission of postoperative RAI was based on histopathology, cervical ultrasound (US), serum thyroglobulin (Tg), and anti‐thyroglobulin antibodies (TgAb) measured within 6 months postoperatively. TL patients required negative US. TT patients required negative US plus Tg < 1 ng/mL if TgAb‐negative, or stable/declining TgAb if positive. Response to therapy was assessed using ATA 2015 dynamic risk stratification and reassessed with ATA 2025 criteria. Results Ninety‐nine patients were included; 84 (84.8%) were women, the mean age was 40.2 ± 13.3 years, and the median follow‐up was 4.8 years. Microscopic extrathyroidal extension was present in 51 (51.5%), lymph node metastases in 37 (37.4%), and extranodal extension in 4 (4.0%). By ATA 2015, 67 (67.7%) had an excellent response and 32 (32.3%) an indeterminate response; no incomplete responses or structural recurrences occurred. ATA 2025 reclassified 3 (3.0%) as low risk, 39 (39.4%) as low‐intermediate, 52 (52.5%) as high‐intermediate, and 5 (5.1%) as high risk. Conclusions Selected intermediate‐risk PTC patients managed without adjuvant RAI had excellent mid‐term outcomes, supporting a risk‐adapted de‐escalation strategy.