What is Proton Beam Therapy? – The new changes in cancer treatment technology
Proton beam therapy – what is it?
We all remember the high profile story of Aysha King in 2014. Aysha was taken abroad by his parents, against the medical advice of his NHS Consultants, to receive proton beam therapy for a brain tumour. Child protection issues and the actions of the hospital pushed this story into the spotlight, as the parents attempted to battle the conventional wisdom of his consultants to treat their child.
A recent US study has now however found that proton beam therapy may actually be better than standard radiotherapy, and is no less effective in attacking and treating tumours. What does this mean for the treatment of tumours in the NHS?
How does proton beam therapy work?
Proton beam therapy works by a ‘laser’ entering the tissue at low energy, and then when the protons hit the tumour, they deposit all of their energy at once in the tumour. The idea is that the treatment is at its strongest when it hits the tumour, but weaker when passing through otherwise healthy, normal tissue.
Standard radiotherapy applies the same strength radiation to all of the area targeted, effectively ‘flooding’ the area with the radiation. This means the healthy tissue is getting the same strength dose as the tumour, and the dose needs to be strong enough to damage the tumour. Naturally, healthy tissue gets injured too as a result. It is clear why many are looking to proton beam therapy as an alternative.
The recent US study found that only 16% of the children tested had serious hearing loss five years after proton beam therapy, compared to 25% with standard radiotherapy. The impact on cognitive impairment was also better, with only 1.5 IQ points being lost per year for proton beam therapy compared to 1.9 for radiotherapy.
What is it good for?
Until now, the discussion in the UK on proton therapy has been focused on brain tumours, particularly in children. This is down in part to the Aysha King story, but is also reflecting the fact that the recent US study looked at brain tumours in children.
However, proton therapy has a much wider scope that can provide benefits to a number of cancers.
In the US for example, it is provided as a treatment option for sarcomas – soft tissue and bone cancers. The delicate nature and location of sarcomas make proton beam therapy a very suitable option. Reduced impact and damage to surrounding tissue is key, as sarcomas often require high doses of radiotherapy treatment, given their aggressive nature. The benefits of a strong treatment that only targets the tumours are obvious.
Proton beam therapy could have a number of applications for all types of cancer, and generally provides a gentler treatment with no set-backs. There is no real reason why it cannot be the go to treatment for most types of cancer requiring non-surgical intervention.
How can I get proton beam therapy?
The only NHS provider of proton beam therapy is currently The Clatterbridge Cancer Centre NHS Foundation Trust, which provides low energy proton beam therapy for eye cancer.
The government has committed £250 million to developing high energy proton beam therapy services in the UK. Two facilities are currently being planned, one in Manchester and one in London, for 2018. The NHS will currently consider applications on their merits for overseas proton beam therapy. However, the Aysha King story shows how hard it may be to obtain this funding, especially given the restrictions on the NHS budget and if treatment is not supported by the treating consultants.
There is another option, effectively between these treatments, that is available more widely in the UK.
Cyberknife radiotherapy treatment works by producing radiation from a small linear particle accelerator, fitted to a robotic arm which allows the energy to be directed at any part of the body. The radiation is the same type as standard radiotherapy, but it is delivered in a more targeted manner, similar to proton therapy. The idea is that you end up ‘flooding’ a much smaller area around the tumour than conventional radiotherapy.
There are currently five hospitals in England that provide Cyberknife treatment. To receive treatment, patients have to apply and receive permission on a case-by-case basis. Again, this can be difficult to obtain, and I have only seen it in cases where the treating hospital is responsible for previously negligent treatment towards the patient. This is of course not to say that it is not provided in cases where there has not been negligence. It is also not to say that it is suitable for every type of tumour, and it does depend on the particular circumstances of the patient.
There is another type of treatment, unavailable at all in the UK for funding or otherwise, with limited availability in the US. It’s called Intensity modulated Proton Therapy. It uses ‘pencil beams’ to focus proton beams to ‘paint’ the radiation dose, spot by spot and layer by layer, onto all parts of a tumour. It’s basically a fully customisable tumour treatment, where you can decide how much and where the treatment should go. It is unfortunately extremely expensive.
Why aren’t these types of treatments more available?
Unfortunately, as with any new treatment, there is an uphill struggle against the conventional treatment. The reality is that the NHS simply cannot afford to replace all of the radiotherapy equipment with new technology that quickly. The other issue is overcoming scepticism about the effectiveness of new treatment.
When Mount Vernon Cancer Centre got their Cyberknife treatment equipment, after spending around £3 million in 2010, the NHS initially wouldn’t let it be used, as they felt it wouldn’t be effective. Proton beam therapy was effectively written off by the NHS for Aysha King’s treatment, and it is only now following the recent US study that hopefully attitudes within the NHS will begin to change. Intensity modulated proton therapy is rare even in the US, due to the expense of the treatment. The technology is there to provide better treatment, but unfortunately the money is not.
My concern is that as knowledge and understanding about alternative cancer treatments develops, and the argument against effectiveness fades, are patients going to be placed at risk of poorer outcomes, purely for cost saving measures?
I think in the future we may start to see clinical negligence cases being brought for failures to offer or fund proton beam therapy or other, more targeted and more therapeutic treatments for cancer. All patient treatment is expensive, however it is a necessity. Furthermore, refusing treatments with less side effects due to cost is short sighted. A patient will less side effects, or with reduced residual injuries, is going to take up less NHS time with additional appointments and treatment. They will also hopefully need shorter gaps between treatment sessions, and therefore the NHS will have more time to treat new patients. Patients health shouldn’t be jeopardised for short-sightedness.
For now, these new technologies are not readily available enough that failure to consider them would guarantee a clinical negligence claim, as any issue would have to be decided on their own merits. However, as the NHS sees the merits in new technology and starts to invest further in these technologies, and support grows across the industry, we will reach a tipping point where the option for proton or Cyberknife, or any other new treatment, is realistic and preferable.
The bigger picture for now of course is whether the NHS is letting patients down in the meantime, while it gets to this position. It is important that regardless of the treatment being offered, the patient is kept informed of all treatment plans. It is important that the patient understands their treatment and is involved with it. If you are concerned about your cancer treatment, either that it is taking too long for treatment or you are unhappy with the treatment being arranged, then it may be grounds for a medical negligence claim.