Proton beam therapy: where are we now?

Proton beam therapy is a relatively new form of radiotherapy that’s garnered a fair amount of media attention in recent months and years.

At the moment, because the proton beam facilities in the UK are limited, the NHS sends certain patients overseas for treatment.

This is far from ideal, so the NHS is planning to open two new proton beam facilities in the UK by 2018, allowing more patients to have access to the technology, while jump-starting UK research.

And several private companies have announced they plan to open facilities too.

But what do we know about the treatment’s effectiveness, and who will benefit from these new proton beam centres?

And looking beyond the headlines, how will the planned NHS and private proton beam facilities compare?

In this post, we’ll discuss what’s on the horizon, and what it means for UK cancer patients.

What’s the current situation?

We’ve covered how proton beam therapy works in a previous post – briefly, it uses streams of proton particles, which can be more tightly focused on tumours compared to x-rays used in conventional radiotherapy, sparing more normal tissue.

Currently the UK has one proton beam therapy facility, at Clatterbridge Cancer Centre. But it’s a ‘low-energy’ machine, only suitable for treating people with rare eye cancers.

Treating more complex cancers requires a ‘high-energy’ beam, so the NHS covers the cost of sending patients for treatment overseas (in the US or Switzerland) when there’s clear evidence that proton beam therapy is the best option. Since 2009, more than 370 patients – mostly children – have received treatment abroad.

When the UK centres open, more patients who are likely to benefit, but who aren’t able to go overseas (either due to poor health or because they need radiotherapy quickly) will have access to proton beam therapy.

Importantly, they’ll also allow further research to understand how to use it. Based on current evidence, the Department of Health estimates that around 1,500 UK patients each year will receive proton beam therapy at the UK centres – roughly one per cent of patients who receive any form of conventional radiotherapy.

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Is proton beam therapy ‘better’?

One of the main challenges in answering this question is lack of evidence from research into the benefits of proton beam therapy. Patients given this form of treatment often have rare cancers, so it’s been hard to run clinical trials comparing it to conventional radiotherapy. And it’s relatively new, so doctors don’t know what the long term benefits are yet.

Dr Adrian Crellin, a radiotherapy expert and NHS England’s clinical lead on proton beam therapy, explains some of the benefits for patients.

“Since it delivers a lower dose of radiation to surrounding tissues, proton beam therapy’s main advantage is in reducing side-effects, rather than improving survival or cure,” he says.

This helps patients whose tumours are near sensitive organs (e.g. the brain or spinal cord) by reducing damage caused to healthy tissue– especially in children, as their organs are still developing.

“For most patients right now, there’s no strong evidence that proton beam radiotherapy is ‘better’ at curing cancer”
– Dr Adrian Crellin, NHS England

There are also suggestions that it can reduce the (small) risk of developing a second cancer later in life.

And, for some rare cancers in adults, the reduced damage to surrounding tissue means proton beam therapy can be given at a higher dose. This, Crellin says, might be more effective at destroying cancer cells, although clear-cut evidence of survival benefit is limited.

“But it’s critical to stress that for most patients right now, there’s no strong evidence that proton beam radiotherapy is ‘better’ at curing cancer, or improving a patient’s chances of survival, than conventional x-ray radiotherapy, ” says Crellin.

That’s why it’s so important that more research is done on proton beam therapy – a point we’ll come back to later.

Coming to the UK

In 2013, the UK government confirmed plans to build two state-of-the-art high-energy proton beam facilities in the UK by 2018 – one at the Christie Hospital in Manchester, the other at UCL Hospital in London – at a total cost of £250 million.

There are also plans to build a research-focused proton beam centre in a new institute at Oxford University – a major investment being supported by the Government and Cancer Research UK, among others.

From 2018, the first cancer patients treated at the new NHS facilities will be those for whom current evidence already recommends proton beam therapy:

• children with several specific types of cancer
• some adults with rare cancers, particularly where tumours have developed near the brain, base of the skull or spine.

This is good news, especially for young children and their families, as it avoids the disruption and stress of international travel.

But could more patients benefit? That’s something we need to find out, and the UK centres will lead to more clinical trials, testing the treatment’s effectiveness in different groups of patients.

But even at full capacity, there will still be a limit on the number of patients the centres treat.

So which patients should be the first to join these trials? UK experts are discussing these questions, to decide where the priorities lie.

Another crucial question is whether some patients shouldn’t be treated with proton beam therapy, because conventional radiotherapy may be just as (or even more) effective for their type of cancer. Proton therapy won’t be suitable for everyone, and it won’t replace conventional radiotherapy.

But alongside the National Proton Beam Therapy Programme, a few private companies have also announced plans for proton beam facilities in the UK, and are saying that NHS patients will be able to use these as early as 2016.

How do these compare to the publicly-funded machines?

What about private centres?

In March, Proton Partners International Limited – a private company – announced plans to build three centres in London, Cardiff, and Newcastle, for nearly £100 million. The company claims the facilities will be ready as early as 2016, and that they’ll treat both NHS and private patients.

Two other companies are planning centres in London’s Harley Street and Moorgate, opening from 2017.

This might seem like good news, increasing the UK’s capacity for treating patients with proton therapy. But there are reasons to be cautious about these headline-grabbing announcements.

Firstly, we don’t know whether – nor how many – NHS patients will be able to use the private centres, nor whether the NHS will be able to afford the amount companies want to charge.

Secondly, if NHS patients are treated at private centres, it’s vital that the treatment they get is as high a standard as the government-funded centres. Yet according to NHS experts quoted in the Daily Mail, the proposed designs for the private centres seem to have less functionality than the NHS facilities.

And thirdly, it’s vital that proton therapy is smoothly integrated into patients’ overall care. Cancer treatment is often complex, and is best provided in a hospital, where different expert teams (such as diagnostic labs, imaging specialists, surgeons, oncologists – and, of course radiologists) can work together seamlessly.

Proton beam therapy is no different; it needs to be given by teams of experts who understand all of the patient’s needs. The current overseas programme relies on good relationships and trust between doctors in the UK and at US and Swiss proton beam therapy centres. If patients are able to use private proton beam centres around the UK, there would need to be a similar situation in place to ensure all aspects of their care remain a top priority.

We’re also worried that patients treated privately might miss out on the opportunity to take part in clinical trials, slowing down vital research on proton beam therapy.

Not putting patients first?

Our final concern is over the alignment of motives. Ultimately, private companies aim to make a profit, so who they decide to treat can be influenced by this, as much as with scientific evidence of benefit.

One of the companies has already said they believe that as many as 10 per cent of patients who currently receive radiotherapy should get proton beam therapy. This is well above the NHS’s estimates, and there’s no evidence to back this up.

One particular point of contention is around prostate cancer. A spokesperson for Proton Partners International Limited recently told the BBC that he thought proton therapy “might benefit 30 per cent of prostate cancer patients”. But studies from the US have suggested that proton beam therapy is no better at treating prostate cancer, nor does it reduce the common side effects (like incontinence and erectile dysfunction).

Despite this, according to the American Cancer Society, the number of US prostate cancer patients receiving proton beam therapy has shot up, as proton facilities become more widely available.

Ultimately, if private centres start offering proton beam therapy to a wider group of patients, even those who won’t necessarily benefit from it, there needs to be extreme care not to fuel the perception of an unfair, two-tiered health system in the UK.

NHS patients must not be made to feel that they are being denied a treatment that is marketed as being ‘better’, nor that they need to part with large sums of money to have the best chances of surviving.

What’s the bottom line?

While there are certain patients who can – and should – benefit from proton beam therapy, headlines about privately-owned centres making the treatment accessible to ‘hundreds more’ NHS patients are a little premature.

As is often the case, the devil is in the detail – and a lot of important details are still unknown, such as whether the facilities will be ready on schedule, provide treatment of a high enough standard, or be properly integrated with NHS care and clinical research programmes.

And despite good intentions, availability for NHS patients will depend on affordability and competing demand from paying customers.

As a final note of caution, despite the media hype, the current evidence suggests that proton beam therapy is unlikely to cure more people than current conventional radiotherapy techniques.

But to know for sure, we need data from clinical trials to determine who could benefit, and should be offered it as standard treatment. It’s only through research and trials – where the UK excels – that we’ll fully understand how best to use this exciting but expensive new technology.

– Emma