ESTIMABL2: thyroidectomy without radioiodine in patients with low-risk thyroid cancer
Skipping radioactive iodine after thyroidectomy for low-risk differentiated thyroid cancer gave the same excellent three-year outcomes as giving it, so most low-risk patients can avoid the treatment.
Overview
Phase 3 non-inferiority trial of 776 patients with low-risk differentiated thyroid cancer (pT1a multifocal to pT1b, N0 or Nx) randomised after total thyroidectomy to postoperative radioiodine (1.1 GBq) or no radioiodine.
At three years, 95.6 percent of the no-radioiodine group and 95.9 percent of the radioiodine group had no event (abnormal imaging, thyroglobulin rise or further treatment), meeting non-inferiority, with no differences in quality of life or adverse events.
- Three-year event-free 95.6 percent (no radioiodine) vs 95.9 percent (radioiodine); non-inferior.
- Events were mostly biochemical rather than structural.
Radioactive iodine is no longer recommended routinely for low-risk differentiated thyroid cancer, supported also by the UK IoN trial.
- Follow-up of three years is short for a disease with late recurrences.
- Applies to low-risk tumours up to 2 cm without nodal disease.