Proton therapy


Proton therapy is a radiotherapy technique that uses a proton beam, unlike conventional radiotherapy machines that use an electron beam. It is a very precise technique that allowsthe delivery of higher radiation doses to the tumor, while sparing the surrounding healthy tissues.

Unlike conventional radiotherapy techniques that use photons or electrons, proton therapy uses a beam of protons. Due to their physical properties, protons can:

  • pass through the tissue and deposit their energy at a given depth and then stop abruptly (unlike photons);
  • limit the damage to the surrounding tissues thanks to their low dispersion during their trajectory, thus limiting secondary effects.

Proton therapy is a high-precision radiotherapy technique that allows the delivery of very high doses to the tumor, while sparing the surrounding healthy tissues. In fact, this technique reduces the radiation dose deposited in the tissues crossed before reaching the tumor, and does not irradiate the tissues located behind the tumor. Moreover, the energy transfer (or deposition) to the tissue by the proton beam is superior to that of photon beams and therefore, might induce more damage in cancer cells and ultimately more killing.

Proton therapy is generally used for pediatric cancers (to decrease the radiation dose received by healthy organs) and for cancers located near high-risk organs, such as head and neck tumors and ocular tumors. Like for all external radiation therapy modalities, side effects may occur. However, due to the proton physical characteristics, these effects are limited.

In France, only three cancer centers have proton therapy equipment: the Institut Curie in Orsay, the Antoine Lacassagne Center in Nice, and the François Baclesse Center in Caen.