Proton therapy: the search for evidence

This illustration shows how, in theory, radiation spreads more widely in the brain when X-rays are used compared to proton therapy. Proton therapy may therefore be better for treating certain types of brain tumour and tumours in children in particular, because the “dose distribution” is more closely confined to the tumour. However, some experts question whether this dose distribution can be achieved in practice and point out that other potentially harmful particles, such as neutrons, could still cause long-term side effects.

 

Brain Tumour UK has compiled a report on proton therapy research. Whilst most brain tumour websites focus only on the claimed benefits for proton therapy, Brain Tumour UK has evaluated the full range of scientific evidence and debate, and reveals that many of these claims are unproven.

Although our report recognises the potential of this targeted radiotherapy, we call for high quality research to measure its true clinical benefits. We call for a clear strategy to conduct high quality research into proton therapy so that, if it is as good as its advocates claim, governments will have the confidence to invest in it in the future.
Proton therapy may be able to treat a small proportion of base-of-skull and other brain tumours, particularly in children, more effectively and with fewer long term side effects that conventional radiotherapy.

But there is a lack of evidence that proton therapy actually delivers clinical benefit in practise. If more people are to benefit from this technology in the future, governments will expect clear evidence that the investment is worthwhile.

To find out more, download our report. And, if you’d like to explore the scientific arguments in more detail, do visit these external links:

2006: Professor Alistair Munro calls for proton therapy progress based on evidence, not opinion

2007: Professor Michael Brada and colleagues find that there is no evidence that proton therapy is the “treatment of choice” for skull-base chordoma and chondrosarcoma.

2007: The Cochrane Cancer Network finds that there is too little high quality evidence to justify the rapid expansion of proton therapy.

10 January 2008: Professors Michael Goitein and James D. Cox argue that randomized trials comparing conventional and proton therapy would be unethical.

20 May 2008: Dr Joel Tepper argues that high quality trials are needed and would be ethical.

20 May 2008: Drs Fergus Macbeth and Michael Williams insist that widespread introduction of proton therapy would be “folly” without better evidence of effectiveness.

20 May 2008: Dr Brett Lewis argues high quality evidence is particularly important when health service budgets are under pressure.

2008: Professor Herman Suit and colleagues say there is no justification for clinical trials of protons.

20 May 2008: Professors Michael Goitein and James D. Cox defend their argument.

20 May 2008: Professor Eli Glatstein and colleagues argue that proton therapy will improve care but trials to measure the benefits are still needed.

18 August 2009: The Department of Health announces its intention to build a proton therapy centre in the UK.

In press: Professor Michael Goitein proposes some options for clinical trials.