"I felt that undergoing such a major intervention simply to swap from daily carbimazole to daily thyroxine wasn’t justified.”

After being diagnosed with Graves’ disease and initial treatment with antithyroid drugs, Chris was offered radioiodine treatment. Unhappy about undergoing a treatment to ‘kill off’ his thyroid, Chris investigated the use of personalised doses of radioiodine aimed at restoring his thyroid levels to normal levels, rather than making him underactive.

He shares his experiences of this.

 

Which condition were you diagnosed with?

Graves’ disease

What symptoms did it cause?

My symptoms had increased gradually, probably over a few years in the late 1980s and early ‘90s, so they’d become quite significant by the time I noticed them. I felt jittery most of the time, had a large appetite, but was losing weight and tended to feel too hot in bed. My handwriting had also become very shaky due to a tremor in my hands.

How were your symptoms picked up on?

I think it may have been a comment from my sister-in-law about my tremor that prompted me to visit my GP. He seemed quite pleased and commented: ‘It’s a classic example of Graves’ disease!’

What treatment were you offered?

My GP explained that I’d first need to take antithyroid drugs (carbimazole) to get my thyroid function back down to normal levels. Once this had been done, he explained that a more permanent treatment involved either surgery to remove part of the thyroid or radioiodine treatment to kill off part of it. 

He also explained that the normal target for treatment would be to remove or destroy enough cells to then leave the thyroid underactive, so I’d subsequently have to take thyroxine tablets for the rest of my life.

I felt that undergoing such a major intervention simply to swap from daily carbimazole to daily thyroxine wasn’t justified, so I chose to remain on carbimazole.

How did you find out about new approaches to treating hyperthyroidism using personalised doses of radioiodine?

In 1997, after taking carbimazole for a few years, I found online reports of research investigating the use of lower, individually calculated doses of radioiodine. The aim of this was to try to provide exactly the right amount of radioiodine to reduce my thyroid activity but leave my thyroid still working properly.

The research was at the Royal Marsden Hospital which was only about an hour’s drive from where I lived. I contacted my GP and asked if it might be possible to be referred to that study, which he did.

It’s worth mentioning that the internet was much more limited in 1997 than it is now. You had to dial in using a modem on your phone line and got much slower data transfer than now. Google didn’t exist; the search engines that were available would return pages ranked by the number of times they included the words you’d searched for.

I’d started using it much earlier than most people, so I was ahead of my GP in my knowledge of this research. And GPs weren’t yet having problems with patients saying they’d read something on the internet but not understanding that not everything online is true, or relevant to them.

How was the personalised dose treatment explained to you?

I can’t now remember the details of the discussions (this was nearly 30 years ago!). I was already well aware of the theory behind the treatment from reading the research papers. I had a science background and understood the statistics relating to risks and benefits. I wasn’t concerned about the risks associated with radioiodine, but it made sense to minimise that risk by having the minimum effective dose. I’d had two hours of driving each time I visited Royal Marsden Hospital, RMH – that probably exposed me to much higher risks i.e. of traffic accidents, than the treatment itself.

How are you feeling now?

Fine, thanks. I was lucky in that the treatment I received back in 1998 turned out to be exactly the right dose so my thyroid levels have remained euthyroid (normal). So I’ve not had to take either carbimazole or thyroxine since then.

The equipment and methods used back then to assess the correct dose were relatively basic compared with those the Royal Marsden Hospital’s Physics department is using in its more recent research. I’m retired now, and it’s good not to be restricted either by my condition or a reliance on tablets.

What have been the most difficult parts of your journey?

None, really. Once I was aware of the cause of my symptoms and the fact that treatments were available, I had no reason to worry. 

My only significant concern was that the standard treatments (via either surgery or radioiodine) should intentionally aim to destroy more of the thyroid than necessary. Once lower, targeted doses had been shown to be effective (the long-term results of the study I took part in were published in 2018), I felt that continuing to offer only the high dose was insulting to patients.

When my daughter was diagnosed with hyperthyroidism a few years ago, I was upset to discover that only the conventional high dose was available. We therefore chose to wait in the hope that another low-dose study might start. So we were very pleased when the chance of personalised dose treatment at the Royal Marsden became available. 

But it concerns me that this was still something I’d had to push for.

Was it difficult for those around you to understand what you were going through?

No. I was able to fit my treatment visits into my normal work schedule. I had to sleep in a different bed from my wife for a couple of days. Before diagnosis, my wife had also wondered why I was wanting such large portions of food, but she was reassured once we understood the reasons.

What would you say to anyone considering their treatment options for hyperthyroidism?

Don’t panic! It’s easily managed with drugs, and longer-term treatments are available. Do your own research, but only via reliable sources of information such as British Thyroid Foundation, British Thyroid Association or academic reports. Be willing to ask about personalised dose radioiodine treatments. If you decide that’s what you want but are told that they’re not available, consider engaging with the authorities to get the system changed.

Medical advisor comment

It is interesting to read Chris’ experiences of this clinical trial and very encouraging to know that Chris’ thyroid function has been stable since having his individualised dose of radioiodine nearly 30 years ago.

People diagnosed with Graves’ disease (autoimmune hyperthyroidism) are usually offered antithyroid drugs for 12-18 months to see whether remission may be possible. Where it has been difficult to stabilise thyroid function with antithyroid drugs, or the Graves’ has relapsed, then often doctors will discuss the options of having ‘definitive’ treatment to kill off the thyroid overactivity. People with toxic thyroid nodules will also often be offered radioiodine or surgery. This may be radioiodine treatment or thyroid surgery. Following this treatment, the majority of people will develop an underactive thyroid (hypothyroidism) and require lifelong treatment with replacement thyroid hormone (levothyroxine).

Understandably, many people are keen to avoid this. Your doctor should discuss the treatment options available and the relative advantages and disadvantages of this. For example, some people may be able to take a low dose of antithyroid drugs long-term, providing their thyroid function and symptoms are stable and the risks of possible side effects have been fully discussed.

As Chris has described, one other possible approach to treating Graves’ disease without causing hypothyroidism is to provide individualised doses of radioiodine. For both Chris and his daughter, this experimental approach has worked; however, most people with Graves’ disease will usually be offered a standardised dose of radioiodine. It is thought that around 60-65% of them will become hypothyroid.

Encouragingly, the NICE guideline on the Assessment and Management of Thyroid Disease recommends that more research is needed to assess whether patients would benefit from a more, individualised approach to radioiodine doses. To date, however, there are sadly no significant studies looking at this.

If you have Graves’ disease and are being offered ‘definitive’ treatment, your doctor should provide you with information about all the available treatment options to help you make an informed choice. Currently, we are not aware of any clinical trials which are looking at individualised radioiodine doses but it is always worth asking your doctor.

Further reading

Hyer SL, Pratt B, Gray M, Chittenden S, Du Y, Harmer CL, Flux GD. Dosimetry-based treatment for Graves' disease  

Taprogge J, Gape PMD, Carnegie-Peake L, Murray I, Gear JI, Leek F, Hyer SL, Flux GD. A Systematic Review and Meta-Analysis of the Relationship Between the Radiation Absorbed Dose to the Thyroid and Response in Patients Treated with Radioiodine for Graves' Disease

NICE guideline on the assessment and management of thyroid disease -recommendations for research

Royal Marsden fact sheets on radioiodine treatment and how it works