A trial to see if radioactive iodine treatment is necessary for low risk thyroid cancer (IoN)
Lots of people have been asking me about my trail and what it entails. I will try and explain it the best I can.
The aim of the trial is to see if radioactive iodine treatment (RAI) is necessary for people who have low risk thyroid cancer.
Radioactive iodine treatment (RAI) is a type of internal radiotherapy. The treatment uses a radioactive form of iodine called iodine 131 (I-131). The radioactive iodine circulates throughout your body in your bloodstream. Thyroid cancer cells pick up the iodine wherever they are in your body. The radiation in the iodine then kills the cancer cells.
Radioactive iodine is a targeted treatment. It is mainly taken up by thyroid cells, having little affect on other cells.
Radioactive iodine treatment may be given:
- after surgery, to kill any cancer cells that may have been left behind
- to treat thyroid cancer that has spread
- to treat thyroid cancer that has come back after it was first treated
Before you have radioactive iodine treatment, you may have a man made type of thyroid stimulating hormone called recombinant human TSH (rhTSH) for a few weeks. It helps any thyroid cancer cells in the body to take up radioactive iodine. Or, your doctor may ask you to stop taking your thyroid hormone tablets. They call this thyroid withdrawal.
You stop taking the tablets for 4 weeks if you are taking T4 (thyroxine) or 2 weeks if you are taking T3 (liothyronine). This is because the I-131 works best when the levels of another hormone called TSH (thyroid stimulating hormone) are high. The levels of TSH in your blood start to rise as soon as you stop taking thyroid hormone tablets.
You will be asked to start eating a low iodine diet 2 weeks before you have radioactive iodine treatment. You need to have a low iodine diet because too much iodine in your body can stop the treatment working so well. You don’t have to cut the following foods out altogether but have as little as you can.
To have radioactive iodine treatment, you go into hospital. You will be looked after in a single room, where you stay alone. You usually stay there for a few days.
You usually have the iodine as a drink or capsule. You won’t be able to eat or drink for a couple of hours so that your body can absorb the iodine. After that, you can eat normally.
The treatment makes you slightly radioactive and you will stay alone in a single room for a few days until your radiation levels have fallen. A radiation monitor (Geiger counter) may be used to check your levels of radioactivity or test anything that is taken out of your room. Some of your possessions may be kept on the ward for a couple of days if they show any radioactivity. After that time, they will be safe again and the nurses will give them back to you to take home.
You should try to drink plenty of fluids to help flush the radioactive iodine out of your system.
Your sweat and urine is radioactive during this time. Your sheets may be changed every day and the hospital staff may ask you to flush the toilet more than once after you have used it.
Being in a room on your own (isolation) protects other people from radiation. Pregnant women and children are not allowed into your room. Other visitors are only able to stay for a short time each day. And the amount of time staff are allowed into your room is limited.
It is important that you know that you are not at any risk from the radiation. The staff in the hospital give this treatment to many people. So, the amount of radiation they are exposed to has to be limited.
Being looked after in a single room can feel lonely. Some people find it frightening. It can help to talk to the nurses about your worries. They can reassure you.
For a few days after radioactive iodine treatment, you will be slightly radioactive. Every day the doctors will come and take measurements from you to work out how much radiation is left in your body. They will tell you when the radioactivity has dropped to a safe level and you can go home.
If you had to stop taking your thyroid hormone tablets, your nurse will tell you when you can start to take them again. Usually, this is 3 days after your treatment.
You will need to take thyroxine tablets to replace the hormones that your thyroid gland normally makes. Your doctors will want to keep your thyroid hormones at a slightly higher level than you would normally need. This is to stop your body producing another hormone called thyroid stimulating hormone (TSH). TSH can help some types of thyroid cancer cells to grow.
The trial will recruit at least 454 people. It is a randomised trial. The people taking part are put into treatment groups by a computer. Neither you nor your doctor will be able to decide which group you are in.
Half the people taking part have radioactive iodine treatment, the other half do not.
The trial team will ask you to fill in some questionnaires
- When you join the trial
- After 2 months
- Between 6 and 9 months later
- Then every 6 months for the next 5 years
The questionnaires will ask about side effects and how you’ve been feeling. This is called a quality of life study.
The trial team will ask your permission to keep a sample of cancer that was removed when you had surgery, and to take an extra blood sample. Researchers will use these samples to learn more about thyroid cancer and how best to treat it.
When you join the trial, you have a blood test and an ultrasound scan of your neck to see how much (if any) thyroid tissue is left after your operation.
You will then have another blood test to measure thyroglobulin levels. Before you have this test, you have to stop your thyroid hormone tablets for a while, or have a drug called recombinant human thyroid stimulating hormone (rhTSH). Whether you stop your tablets or have rhTSH will depend on the usual practice at the hospital where you are having your treatment.
If you are in the group having radioactive iodine, you will have this after having the scan of your neck, possibly on the same day. You may stay in hospital for between 1 and 3 days while the radioactive iodine takes effect. If you stopped taking your hormone tablets, you can start them again about 2 days after having the radioactive iodine.
If you are in the group not having radioactive iodine treatment and you stopped taking your hormone tablets, you can start them again straight after having the blood test.
You have a blood test 2 months later. The doctors may change the dose of thyroid hormones you take after looking at the result of this test. You will not have to stop your hormone tablets or have rhTSH at this visit.
Between 6 and 9 months after having the first neck ultrasound scan (and radioactive iodine treatment if you had it), you have another ultrasound scan and a blood test. You will also have a 2nd blood test to measure thyroglobulin levels. As before, you have to stop your hormone tablets for a while, or have rhTSH for 2 days before this blood test.
You then go to hospital every 6 months for the next 5 years. You have a blood test at each visit. You have an ultrasound scan twice in the 1st year and then once a year for the next 4 years.
So this is has been my life for 3 years now. Another 2 more to go.
It just goes to show the money people donate to Cancer Research really does help. Without donations this trial wouldn’t exist. I volunteered to participate in this trial so others potentially wouldn’t have to go through the ordeal that I did. This whole journey was so hard for me and my family so I want to help change it for people in the future.