When is radioactive iodine therapy recommended for thyroid cancer?

The treatment uses a radioactive form of iodine that is absorbed by thyroid cells more readily than most other tissues. It can destroy remaining normal thyroid tissue and iodine-absorbing cancer cells. It is mainly considered for differentiated thyroid cancers, such as many papillary cancers; it is not useful for every thyroid cancer type.

The decision uses the surgical pathology, scan findings, tumour features and thyroid-stimulating hormone plan. The team also considers kidney function, pregnancy status and breastfeeding because radioactive iodine needs specific safety precautions.

Your team may ask you to follow a low-iodine diet for a short period, adjust thyroid hormone, and complete blood tests or imaging. Follow radiation-safety instructions about distance, hygiene and contact with other people for the period specified by your treatment team. Tell them if you are pregnant, might be pregnant, breastfeeding, or taking iodine-containing medicines.

Ask how the dose will be given, whether you need to attend alone, how to manage dry mouth or nausea, and when thyroid hormone can be restarted or adjusted.

Seek urgent advice for breathing difficulty, marked neck swelling, inability to swallow fluids, severe vomiting, or signs of dehydration. Contact the treating team about persistent neck pain, troublesome salivary-gland swelling, or symptoms that become harder to manage after treatment.

Does my tumour type absorb iodine? What finding makes treatment worthwhile for me? How should I prepare, and how long will precautions last? What symptoms should I report? How will follow-up scans and thyroid hormone treatment be arranged?