Radioiodine (RAI) has played a crucial role in differentiated thyroid cancer treatment for more than 60 years. However, the use of RAI administration in patients with papillary thyroid microcarcinoma (even multifocal) is now being widely discussed and often not recommended.
In accordance with European consensus, and contrary to the American Thyroid Association (ATA) guidelines, we recently performed RAI thyroid remnant ablation in a patient with differentiated papillary multifocal microcarcinoma. The post-therapeutic whole-body scan and SPECT/CT revealed the real and unexpected extent of disease, with metastases to upper mediastinal lymph nodes.
This finding led to the patient's upstaging from stage I to stage IVa according to the American Joint Committee on Cancer/International Union Against Cancer criteria.