Radioactive iodine after thyroidectomy

Thyroid cells can take up iodine from the bloodstream. Radioactive iodine uses that feature to deliver radiation to thyroid tissue left after surgery. It may be considered for selected thyroid cancers, depending on the tumour type, pathology, spread and risk of recurrence. It is not needed after every thyroidectomy. The treatment is taken as a capsule or liquid, and the team may monitor thyroid blood tests and tumour markers during follow-up.

Short-term effects can include dry mouth, altered taste, nausea, neck tenderness or swelling, and soreness of the salivary glands. Longer-term concerns can include ongoing mouth dryness or changes in saliva. Your specialist will explain individual risks and ways to protect hydration and oral health.

Follow the team’s instructions about thyroid hormone medicine and diet; preparation may be needed so thyroid cells take up the iodine effectively. Tell the team if you are pregnant, breastfeeding, or planning pregnancy. Arrange practical support at home, sleep separately if advised, keep distance from children and pregnant people when instructed, and use careful toilet and hand hygiene. Do not change hormone treatment or diet without the nuclear medicine team’s plan.

Contact your treatment unit for persistent vomiting, inability to drink, marked neck swelling, severe neck pain, or swelling around the salivary glands. Seek urgent care for trouble breathing, sudden facial or throat swelling, fainting, or signs of severe dehydration. Keep following radiation-safety instructions while arranging help.

Ask why radioactive iodine is recommended, how to prepare with hormone medicine and diet, how long precautions last, how to protect household members, which symptoms need same-day advice, and when blood tests or scans will check the response.