Proton therapy is a form of radiotherapy used to treat cancer, which is capable of striking only the tumor while preserving healthy tissue and allowing more intense doses of radiation to be delivered, thus increasing the chances of successful treatment. This is because while conventional radiotherapy uses X-rays or electrons, proton therapy involves the use of protons, i.e., heavier atomic particles with greater energy than electrons and therefore more precise and effective. With proton therapy, energy is released at a particular depth of the tissue, the so-called Bragg peak.
The proton therapy for cancer treatment was first proposed in the 1940s and subsequently tested in the 1950s. The first hospital dedicated to this therapy dates back to the 1990s; it was built in Loma Linda U.S. and today it still constitutes an essential reference point worldwide. Since then, more than 80 structures have been set up in various parts of the world and many others are under construction or planned. Over 130,000 patients have been treated worldwide.