After radioactive iodine treatment for thyroid cancer

Thyroid medicine after radioactive iodine treatment

You will need to take thyroxine tablets. These replace the hormones that your thyroid gland normally makes. Your doctors will want to keep your thyroid hormone levels slightly higher than normal. This is to stop your body producing another hormone (thyroid stimulating hormone, or TSH). TSH can help some types of thyroid cancer cells to grow.

The doctors will work out the correct dose for you and when to start taking it.

Radiation safety precautions

You need to follow safety precautions for a few days after your treatment. This is to protect others from the radiation. 

The advice about precautions varies for different people and for different hospitals. Talk to your doctor, specialist nurse or medical physicist. They will explain how long you need to limit yourself.

These precautions include:

Keeping your distance and avoiding close contact with people

Stay away from crowded places and avoid using public transport. If you live or work with other people, you will need to keep a distance from them. Avoid standing or sitting close to them. This stops them from getting radiation from you. 

Your doctor will tell you not to have close, lengthy contact with others for a couple of weeks. This includes babies, young children, pets and pregnant women. Avoid hugging and kissing other people.

Not sharing a bed

You might need to sleep in a separate bed if you normally share a bed. Check if this applies to you and ask how long this should be for.

Avoiding sexual contact

You might need to avoid sexual intercourse for a period of time or to use a condom. Check if this applies to you and ask how long this should be for.

It is also recommended that:

• women use reliable contraception for at least 6 months

• men use reliable contraception for at least 4 months

Practicing good hygiene

A small amount of radiation will still be in your sweat, urine and saliva. For a few weeks you will need to use your own towel and keep your cutlery and plates away from others until washed. Continue to flush the toilet twice and wash your hands thoroughly after using the toilet.

Travelling after radioactive iodine treatment

Recent treatment with radioactive iodine may set off radiation alarms at airports. Talk to you doctor if you plan to travel abroad. You can have a certificate from the hospital, or a letter from your doctor. This explains the treatment you have had.

Possible short term side effects

The side effects of radioactive iodine treatment vary depending on:

• your age

• whether you have other medical conditions

• the dose of radioactive iodine you have 

Some people may have one or more of the following short term side effects:

Inflammation of the salivary glands

Your salivary glands can become inflamed after treatment. This can cause symptoms such as swelling and pain. You can have painkillers to help with the inflammation.

Dry mouth

You may make less saliva (spit) and feel like your mouth is dry. This usually gets better with time, but in a few people it may be permanent.

To reduce the risk of getting this side effect, it can help to drink plenty of fluids during your hospital stay. Some doctors recommend that you chew gum or suck sweets to keep the salivary glands working. If you have a dry mouth, you could try using artificial saliva to see if this helps. Your doctor or nurse can arrange this for you.

Changes to your taste

You may have short term changes to your taste and smell. This may not start until you get home. It usually gets better within 4 to 8 weeks. It can help to drink plenty of fluids after your treatment.

Go to more information about coping with mouth problems

A swollen or tender neck and feeling flushed

Some people may have a feeling of tightness or swelling in their neck for a few days after treatment. This is more common if you still had a large part of your thyroid gland. Some people also feel flushed. Rarely, people can feel pain in their neck.

Tell your doctor or nurse if any of these symptoms happen. They can give you a painkiller or a medicine to reduce inflammation, which can help.

Feeling sick (nausea)

You may feel sick for the first few days after treatment. Your doctor or nurse can give you anti sickness medicine to help with this.

Inflammation of the tummy (gastritis) and bladder (cystitis)

The treatment can inflame the lining of your tummy or bladder. 

Symptoms of an inflamed tummy (gastritis) include:

• feeling and being sick

• heartburn

• diarrhoea

Symptoms of bladder inflammation (cystitis) include:

• burning or pain when you pass urine

• needing to pass urine urgently or more often than usual

• feeling that you haven't finished passing urine when you have or that you need to pass urine again as soon as you've been

Talk to one of your team if you have any of these side effects.

Possible long term side effects

Possible long term side effects include:

Further radioactive iodine treatments

Some people might need more than one radioactive iodine treatment. This is to make sure the treatment destroys all the remaining thyroid tissue and cancer cells.

Find out about your follow up appointments