Proton beam therapy is a new type of radiotherapy using protons rather than x-rays to kill cancerous cells in tumours.
The advantage is that the proton beam can be tuned so that virtually all the energy is deposited in the tumour, minimising the damage to surrounding healthy tissue – a crucial consideration in the case of brain tumours.
Reducing a patient’s exposure to radiation also reduces the risk of cancer recurring in the future. This is particularly important for children, as there will be many decades before any mutation that might be introduced into cells during radiotherapy will potentially develop into secondary cancers.
The treatment has been offered by the NHS to patients who were likely to benefit, although it is not yet available in