Download and print as a PDF (290kB pdf)
Department of Nuclear Medicine
What is this information about?
This information is about your radioiodine treatment.
Why have I been given this information?
You have been given this information because your doctor has referred (sent) you for a radioiodine treatment.
Reading this information can help you to know what to expect from your treatment. Following the advice will help to make sure that the treatment goes as well as it can.
What is Nuclear Medicine?
Nuclear medicine:
- is a safe and painless technique which provides medical images of the body.
- uses small amounts of radioactive materials as tracers to diagnose or treat disease. In diagnosing a condition, the radiation is detected by a special type of camera called a “Gamma camera”.
What is a radioiodine treatment?
Radioactive iodine (radioiodine) is used to treat overactive thyroid, a condition known as hyperthyroidism. It has been used as a safe and effective treatment for over 70 years.
The radioactivity:
- destroys overactive thyroid tissue
- aims to lower your thyroid function to normal levels.
Are there any alternative treatments?
Alternatives to radioiodine treatment include:
- anti-thyroid medications such as carbimazole or propylthiouracil (PTU). These may be used to control overactive thyroid for a limited time.
- surgery to remove the thyroid gland completely.
We usually try to treat overactive thyroid with radioiodine first rather than an operation (it is the ‘first-line’ treatment). We may also use it if anti-thyroid medication is no longer working to control your overactive thyroid.
What can I expect during my appointment?
- We will discuss any concerns and questions you may have about the treatment and its effects. This includes the ‘distance restrictions’ that you should follow after the treatment.
- The radioiodine is given in a small capsule that you swallow with water. It has no taste and does not have any effects straight away. Please note the capsule contains gelatine made from animal products.
- Before leaving the department, you will be given:
- a yellow form that describes your treatment and the restriction times
- a 6 to 8 week follow up blood test form
- a copy of your consent form.
How can I prepare for my radioiodine treatment?
- Eating and drinking. You can eat and drink as usual before the treatment.
- Medications. If you are taking antithyroid medications your body does not take in the radioiodine as well. We will advise you when to stop them before your treatment.
Might I have an allergic reaction to the radioactive iodine?
Allergic reactions to the radioiodine are very rare but can happen.
Be aware,
radioactive iodine may make thyroid eye disease worse. If you have eye problems, tell your doctor as we may need to take special precautions or delay your treatment.
Can I have a radioiodine treatment if I am pregnant or breastfeeding?
No. We will check your pregnancy status with you before the treatment. If you are, or think you may be, pregnant or breastfeeding you must tell us as soon as possible. You will need to stop breastfeeding if you plan to have this treatment.
Are there risks to having children after the treatment?
The treatment does not affect male or female fertility.
Be aware,
after radioiodine treatment:
– men should avoid fathering a child for at least 4 months
– women should avoid conceiving for 12 months
Are there any risks?
We are all exposed to natural background radiation every day. This comes from the ground, building materials around us, the food we eat and from the sun.
This treatment will give you an extra radiation dose on top of this. The amount depends on the type of treatment you are having. It ranges from a few days’ natural background radiation to a few years.
After weighing up the risks and benefits your doctor has decided that having the treatment is right for you. They believe that the potential benefits outweigh the risk.
Long term studies show the only effect known from having radiation treatment is a very small increase in the chance that you might get cancer many years or even decades after the exposure.
These risk levels are a very small addition to the 1 in 2 chance we all have of getting cancer at some point during our lifetime.
Are there any risks to others?
Following the treatment, you will receive a safety instruction card (yellow form). This tells you what you should do to keep your friends and family safe after your radioiodine treatment.
This advice aims to minimise the radiation dose to friends and family.
Be aware:
– by following the advice, other people will only receive a very small radiation dose from spending time with you. This will not be dangerous for them.
– you will be able to carry out normal day-to-day household activities.
– you will need to reduce the amount of close contact that you have with other people
– the amount of time that you must follow these restrictions depends on how large a dose of radioiodine you have had.
How must I restrict my contact with other people after my radioiodine treatment?
Follow the restrictions below. We will explain them to you.
| Partner | You should sleep apart from your partner for 11 to 13 days. |
| Adults & Children over 5 yrs | Avoid spending over 15 minutes a day in close contact (under a meter). Do this for 11 to 13 days. |
| Children under 5 years & Pregnant People | Avoid spending over 15 minutes a day in close contact (under a meter). Do this for 21 to 25 days. |
| Places of entertainment | Avoid for 11 to 25 days. |
| Travel | Avoid journeys on public transport of over 1 hour for 11 to 25 days. When using private transport, sit in the back, away from the driver. |
| Returning to work | Stay off work based on the guidance above on contact with others. How soon you can return to work will depend on the type of contact you have with other people at work. |
Where should I go for my treatment?
You will have your treatment in the Nuclear Medicine Department, St Richard’s Hospital.
Use the main entrance to the Outpatients Department. This is in the South Wing of the hospital.
Once you are inside the Outpatients Department, turn right and take the stairs or lift to the Department of Nuclear Medicine on the first floor.
Wheelchairs are available just inside the entrance on the ground floor.
If you are arriving by car, please use hospital entrance number 2.
If you need to park, use the ‘pay on foot’ car park close to the entrance to the Outpatients department (South car park). Pay at the end of your parking session using the machines in the Outpatients department entrance. Disabled parking bays are available for the registered disabled near the main Outpatients’ entrance.
How long will the treatment take?
Radioiodine treatment can take between 15 to 30 minutes.
Who will be at my treatment?
A radiographer or a clinical scientist will be with you in the room during the treatment.
After your appointment
Most patients do not notice any side effects from the treatment. You may experience a slight discomfort in the throat in the first 2 or 3 days. You can use your usual pain killers (such as paracetamol) that you buy at a pharmacy or shop to relieve this
It can take between a few weeks and a few months for the therapy to have its full effect.
Around 7 in 10 patients (70%) will develop hypothyroidism (underactive thyroid). We will check your thyroid hormone levels regularly to see whether this happens to you.
Up to 1 in 10 patients (10%) will need a further dose of radioiodine and some patients who continue to have symptoms of hyperthyroidism will need to return to their anti-thyroid medication for a limited time.
You should receive a follow-up appointment with your doctor from the outpatient department, around 4 months after your treatment to check on your progress. If you do not get an appointment letter, please contact the secretaries in the Endocrinology department.
Can I drive home after my treatment?
Yes. Any escort should sit in the back of the vehicle.
Can I bring someone else with me to my appointment?
Yes. You can bring someone, such as a friend, relative or carer with you. They must be over the age of 16
Important:
Be aware,
you may not bring children under the age of 16 or pregnant people with you to your appointment. There is no child-minding service at the Trust. You must make your own arrangements for childcare while you are having your appointment if you need to.
What should I do if I cannot come to my appointment?
We have ordered in a radioiodine capsule which can only be used for your appointment, at the time you have been given.
We cannot use it for someone else’s appointment. Because of this, you must let us know as soon as possible if you are unable to attend.
Be aware,
it is Trust policy that you will not be offered a further appointment if you do not attend a booked appointment.
This means that you will need to return to the doctor who referred you for the treatment.
How is my medical data protected?
Everyone working within the NHS has a legal duty to keep patient information about you confidential & secure. If you have any concerns around the use of your medical and diagnostic imaging information, copies of the “Care Record Guarantee” and “Your Medical Data” leaflets can be downloaded from:
UHSxYou can get a printed copy of these leaflets from the PALS (Patient Advice and Liaison) office at Worthing or St Richard’s, Chichester, Hospitals.
Who can I contact if I need further information or support after I have read this information?
For further general information on Nuclear Medicine and radioiodine treatments visit the:
or the British Thyroid Association webpage
If you have questions or need further information about your Radioiodine Treatment, please contact the Nuclear Medicine Department (staffed Monday to Friday):
Nuclear Medicine Department,
St Richard’s Hospital,
First floor, Outpatients block (South Wing)
I need help with transport to my appointment for medical or financial reasons. What help is available?
To find out what help with transport you may be able to get please visit the
To enquire about booking the hospital transport service phone
Hospital transport
0300 777 4444
To check whether you can get help with the cost of transport, phone the St Richard’s Hospital switchboard and ask for the Cashiers Office.
St Richard’s Hospital switchboard
01243 788122
Be aware,
you should do this before your appointment.
This leaflet is intended for patients receiving care in St Richard’s Hospital.
The information in this leaflet is for guidance purposes only and is in no way intended to replace professional clinical advice by a qualified practitioner.
Today’s research is tomorrow’s treatments. That’s why UHSx is proud to be a research-active Trust. Find out how you can get involved.
Visit our website www.uhsussex.nhs.uk/research-and-innovation/information-for-patients-and-public or scan the QR code: 