Mallick U, Newbold K, et al. Thyroidectomy with or without postoperative radioiodine for patients with low-risk differentiated thyroid cancer in the UK (IoN). Lancet 2025.

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The Clinical Question

For decades, postoperative radioiodine (RAI) ablation has been standard after total thyroidectomy for differentiated thyroid cancer. But for low-risk patients, is this actually necessary?

The French ESTIMABL2 trial showed patients with very small tumors (pT1a/b, N0/Nx) could skip ablation. But what about larger pT2 tumors? And what about long-term outcomes?

Key Results

Non-inferiority was achieved. Patients who skipped radioiodine had equivalent outcomes over 6.7 years of follow-up.

Bottom Line

For pT1 or pT2 tumors with N0/Nx nodal status: Radioiodine ablation can be safely omitted.

For pT3 or N1a disease: Evidence is insufficient, continue current practice.

Full Paper: https://doi.org/10.1016/S0140-6736(25)00629-4

Head and Neck Oncology journal Club

Krishnakumar Thankappan

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