This treatment is sometimes called radioactive iodine ablation or thyroid ablation.
Learn more about:
- Overview
- How to prepare for RAI treatment
- Having RAI treatment
- Safety precautions during RAI treatment
Overview
Also called radioactive iodine ablation or thyroid ablation, this treatment destroys any remaining cancer cells and thyroid tissue left after surgery. It uses radioactive iodine (RAI) or I-131 that you take as a tablet in hospital.
RAI kills thyroid cells and thyroid cancer cells while having little effect on other body cells. You have RAI treatment weeks or months after surgery, when any swelling has gone down.
When is RAI used?
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Preparing for radioactive iodine treatment
Limit foods high in iodine
From 2 weeks before RAI treatment, avoid seafood, iodised salt, sushi, some dairy foods and certain food colourings.
Tell your doctor about recent imaging scans
Any CT or other scans using iodine dye (contrast) in the past 2 months can affect RAI treatment.
Raise TSH levels
For RAI treatment to work, you need to have a high level of TSH in your body.
To raise TSH levels, you will usually have injections of a synthetic type of TSH hormone (called rhTSH). You are given an rhTSH injection each day for the 2 days before your RAI treatment.
In rare cases, instead of injections, you may raise your TSH levels by stopping your thyroid hormone replacement medicine for 3–4 weeks. You will need blood tests, to check that TSH levels are high enough, before you have RAI treatment. Talk to your doctor about ways to manage any hypothyroidism symptoms (see page 3) that develop in this period.
Your doctor will explain when to start taking your thyroid hormone replacement after RAI treatment.
RAI may have a short-term effect on eggs and sperm, so wait 6 months before trying for a baby. You need normal thyroid hormone levels before getting pregnant. Ask your doctor about fertility and RAI.
Having RAI treatment
You go to hospital the day you start treatment. After swallowing the RAI tablet, your body fluids will be radioactive for a few days, so you will need to stay in hospital for 1-3 days. Ask your team questions before you go to hospital, so you know what to expect.
Once the radiation has dropped to a safe level, you can go home. If you had the synthetic TSH injections, this usually takes a day.
A few days after treatment, you will usually have a full body scan to check for any remaining thyroid cells. It’s normal for the scan to find some thyroid cells in the neck as small amounts of healthy thyroid tissue remain after surgery. RAI takes several months to destroy this tissue. The scan may also show if cancer has spread to lymph nodes or other areas.
Side effects
These are usually temporary and drinking lots of water helps the radiation pass out of your body faster, reducing your bladder’s exposure to radiation. Some side effects, such as tiredness, are often from thyroid hormone withdrawal, and improve when your levels return to normal.
The salivary glands may absorb some iodine, leaving a dry mouth or taste and smell changes for a few weeks. You may have dry or watery eyes.
Safety precautions during RAI treatment
While in hospital you will be in a room by yourself. You may not be allowed visitors, or only short visits where people stay 2–3 metres away from you. Pack an electronic device, book or game so you’re not bored. When you go home, you will need to take some safety measures for the first few days. These include:
- sleeping alone
- washing clothes, towels and sheets separately
- washing your hands, especially before making food
- sitting down to pee and closing the lid when you flush.
→ READ MORE: External beam radiation therapy
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A/Prof Diana Learoyd, Endocrinologist, GenesisCare North Shore, St Leonards and University of Sydney, NSW; Sally Brooks, Senior Pharmacist, Peter MacCallum Cancer Centre, VIC; Monica Kwaczynski, 13 11 20 Consultant, Cancer Council WA; Susan Leonard, Clinical Nurse Consultant – Thyroid Cancer, Royal Brisbane and Women’s Hospital, QLD; Juliette O’Brien OAM, Consumer; Jonathan Park, Consumer; A/Prof Robert Parkyn, Breast and Endocrine Surgeon, St Andrew’s Hospital and The Queen Elizabeth Hospital, SA; A/Prof David Pattison, Director, Department of Nuclear Medicine and PET Services, Royal Brisbane and Women’s Hospital, QLD.
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