What is proton therapy?

Proton therapy is an innovative radiation therapy technique that uses proton beams instead of photon beams (X-rays), as in traditional radiotherapy.

From cell to tumour

All human tissue is made up of cells. These can divide when necessary, for example to replace old or damaged cells. If cell division is disrupted and cells divide uncontrollably, a growth (tumour) may develop. This can be benign or malignant. A malignant tumour or cancer can grow into the surrounding healthy tissue, causing the cancer to spread.


Radiation can kill or damage all types of cells in the body, but cancer cells are more sensitive to radiation than healthy cells. Indeed, healthy cells are better at recovering from light radiation damage than cancer cells.

Radiation or radiotherapy occupies an important place in the treatment of patients with cancer. About 40-50% of all patients with cancer are treated with radiotherapy at some point during the disease, whether or not in combination with chemotherapy and/or targeted medication. The majority of irradiated patients are treated with the intention of curing, but radiotherapy also plays an important role in alleviating symptoms.

Radiation techniques

Radiotherapy is possible by means of several techniques. The most optimal radiation technique is chosen based (among other things) on tumour type, size and shape, location and position in relation to surrounding healthy tissue.

The aim is always to deliver a maximum radiation dose to the tumour to damage and destroy it while minimising the exposure of healthy tissue to protect it.

Despite major technological advances in recent years, in some specific situations it remains difficult to adequately spare the healthy tissue surrounding the tumour when using classic radiotherapy techniques (e.g., in young patients or for tumours close to highly sensitive structures). Proton therapy can provide a solution here: in certain cases it reduces the radiation load on the healthy tissue while the radiation dose to the tumour remains the same.


Last edit: 5 June 2023