A new radiotherapy technique that protects women with breast cancer from life-threatening side-effects could soon be available to more patients.
The technique, called deep inspiration breath-hold, essentially means that patients take a deep breath and hold it just before each radiotherapy dose is delivered. This protects the heart from damage caused by the radiation.
More than 80 per cent of women diagnosed with breast cancer will have radiotherapy to kill off cancer cells as part of their treatment.
However, while it is a highly effective treatment, radiotherapy — which uses beams of radiation to damage the DNA of cancer cells, causing them to die — can raise a woman’s risk of heart attack.
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That’s because the heart lies just behind the left breast and, as radiotherapy is targeted at the breast, it can also damage the heart and nearby blood vessels.
This, in turn, can cause the tissue to become thickened and inflamed and, over time, may block blood supply to the heart, increasing the risk of heart disease and heart attack.
The idea with the deep inspiration breath-hold (DIBH) technique is that, as the patient takes a deep breath in, the lungs expand and push the heart backwards and downwards, away from the breast area and out of danger.
A number of machines can be used to monitor a patient’s breathing to make sure radiation is given only when the patient breathes in, the lungs are fully inflated and the heart is out of harm’s way.
But experts also say patients can, with the right guidance, simply take a deep breath in just before a dose is applied without the need for expensive machines.
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So far, 28 out of the 60 NHS radiotherapy centres in the UK and many private hospitals offer DIBH using a range of equipment and staff trained to deliver the technique — and it should be available everywhere next year, according to the charity Action Radiotherapy.
The Royal College of Radiologists and the National Institute for Health and Care Excellence (NICE) are now reviewing guidelines to decide if DIBH should become a standard part of radiotherapy treatment for breast cancer patients.
In the meantime, experts want to raise awareness of the technique, which can be used with external beam radiotherapy that makes up 95 per cent of breast cancer radiotherapy.
Doctors developed the idea of DIBH around 15 years ago in response to concerns that, as breast cancer patients are surviving longer thanks to advances in diagnosis and treatment, increasing numbers are going on to develop heart problems.
One study of more than 2,000 women in the New England Journal of Medicine found that breast cancer patients who had received radiation to the heart were more likely to suffer ‘major coronary events’.
Radiation is measured in units called ‘Grays’ and the researchers found the rate of coronary events rose by 7.4 per cent for every Gray of radiation delivered to the heart. The average dose to the breast was 4.9 Grays.
According to Dr Anna Kirby, a consultant oncologist at the Royal Marsden NHS Foundation Trust, reducing the average radiation doses received inadvertently by the heart from 3 Grays to 1 Gray would cut the number of radiation-related heart attacks in breast cancer survivors in the UK from 19,500 to 6,000 by 2040, and the number of deaths from heart disease from 9,000 to 2,000.
She adds: ‘The use of heart-sparing breast radiotherapy techniques is likely to reduce the incidence of radiation-related cardiovascular disease significantly in survivors of breast cancer.’
A review of the use of DIBH, published last year in the Journal of Medical Radiation Sciences, concluded that it has ‘consistently been shown to lower the [radiation] dose received by the heart’.
In one Canadian study of 50 patients, published in the journal Practical Radiation Oncology in 2014, DIBH reduced the radiation dose to the heart by 75 per cent, compared with those who ‘free breathed’ (i.e. breathed normally). The breath-holding technique has been shown to be a ‘very effective technique in reducing long-term side-effects’ for women with left-sided breast cancer who have radiotherapy, says Professor Pat Price, a radiation oncologist and chair of Action Radiotherapy.
‘There are many specialised forms of radiotherapy treatments and techniques such as DIBH now becoming available on the NHS,’ she says.
The problem is that not all patients are aware that radiotherapy — and DIBH — is available to them.
‘We need to do more to tell women about this simple technique, which could reduce the risk of incidental radiation dose to the heart,’ she adds.
One patient to benefit from the technique is Alison Young, a management professional from London, diagnosed with cancer in both breasts in 2015. After undergoing six months of chemotherapy, she had a double mastectomy in March this year to remove an aggressive 4cm tumour in her left breast, a non-life-threatening tumour in her right, and all the lymph glands on her left side.
This was followed by a further course of chemotherapy, and the 52-year-old single mother of one, underwent three weeks of radiotherapy to the left side of her chest. Alison was offered DIBH as part of her radiotherapy treatment, which she underwent privately at the Leaders in Oncology Care clinic in London, using her work-place medical insurance.
‘I knew about chemotherapy and surgery, but didn’t know about radiotherapy, so it was new to me to learn that radiotherapy to the left side can damage the heart,’ says Alison, who has an eight-year-old son.
The DIBH technique felt really empowering. For the first time, I could control my cancer treatment, quite simply with my breath.’
Each radiotherapy session took around 20 minutes, with Alison lying on a hard, flat board. Once she was in the right position, she had to keep perfectly still while the radiotherapy was given — she had sensors across her chest to monitor her breathing, which was represented by a bar on a screen in front of her.
As she inhaled, the bar rose and, once it reached the point where there was the maximum amount of air in her lungs, she had to hold her breath at that level and keep completely still while the radiotherapy dose was administered. Too much or too little air in her lungs and the radiotherapy machine automatically cut out.
‘By holding my breath and moving my heart out of the way of the radiation beams, they were able to give a higher dose of radiation in a much more targeted way,’ explains Alison.
It can be more difficult than conventional radiotherapy for those who find it hard to hold their breath.
‘Keeping just the right amount of breath in your lungs for that time does require a bit of concentration, and there were certainly times when we had to do one beam again,’ says Alison.
Though DIBH is predominantly being used on women with breast cancer, it could also benefit patients with lung cancer or lymphoma (cancer of the lymphatic system), as both groups may receive radiation.
Before having radiotherapy with DIBH, patients have to be coached by specially trained medical staff to hold their breath and are often encouraged to practise holding their breath for 20 seconds at a time at home beforehand.
However, the technique is not suitable for everyone.
It is not necessary for women having radiotherapy to their right breast (because the heart is on the other side), and may not be suitable for some needing treatment to the left.
‘Whether or not it is suitable will depend on your anatomy and precisely where your heart lies in relation to the treatment area, explains Professor Price. ‘Everyone is slightly different.’
But, given the upcoming review, patients should be aware of the technique and ask about it, she says: ‘If it hasn’t yet been rolled out at a patient’s centre, the consultant will be able to advise on the best course of action.’
Alison also urges all women undergoing radiotherapy to their left side to ask about DIBH: ‘It is such a simple technique — but one that is both empowering and which can prevent health problems in the future. It’s a win-win situation.’
Daily Mail