A New Hope : Proton Beam Cancer Therapy

A US study found the technique caused fewer side effects than conventional radiotherapy. The technique is an alternative to standard radiotherapy.

Photon beam therapy uses beams of protons (sub-atomic particles) to destroy cancerous cells. Unlike conventional radiotherapy, the beam of protons stops once it "hits" the cancerous cells. This results in much less damage to surrounding tissue.

This was a prospective cure by looking at the side effects and survival outcomes of using proton radiotherapy to treat children and young people (aged 3 to 21 years) . Proton beam therapy (also known as proton radiotherapy) seems promising in being able to be given at a lower and more targeted dose than standard (photon) radiotherapy, and is increasingly used to minimise side effects of treatment.

A Proton radiotherapy study  was carried out by researchers from Massachusetts General Hospital, Brigham and Women’s Hospital in Boston, and Winship Cancer Institute of Emory University in Atlanta, US. The study was funded by the US National Cancer Institute and Massachusetts General Hospital, and published in the peer-reviewed medical journal The Lancet Oncology.

The Proton radiotherapy  research as concluded by the researchers resulted in acceptable toxicity and had similar survival outcomes to those noted with conventional radiotherapy, suggesting that the use of the treatment may be an alternative to photon-based treatments.

Overall, the results seem positive. The difficulty is that this is a non-comparative trial. All children received proton radiotherapy. There was no randomised comparison group with similar characteristics in terms of tumour type, stage, surgery and chemotherapy treatment who instead received standard radiotherapy, to directly compare complications and survival outcomes. Ideally, a large number of children randomised to the same dose schedule of the two forms of radiotherapy would be needed to give the best comparative information on effectiveness and safety.

However, the researchers say: "Although a randomised trial is the best way to obtain a proper comparison cohort, both clinical leaders in the UK and the US deem randomised trials of proton and photon radiotherapy in children to be both unethical and not feasible". This means that such trials are unlikely to be carried out, and this type of prospective non-comparative study is likely to be the best evidence available.