From time of Wilhelm Roentgen and Maria Skłodowska Curie ionizing radiation is applied for cancer treatment.

Ionizations lead to DNA double strand breaks which stops division of cancer cells. The efficiency of this therapy grows with the precision of tumour irradiation. The challenge is to irradiate the tumour and to spare healthy tissue. Nowadays megavoltage X-rays from linear electron accelerators are used in clinics but the high penetration of photons limits the possibility of sparing healthy tissue.

In 1947 Robert Wilson noticed that for proton beam entering body dose is the lowest, maximal at the proximal part of the proton track and practically zero at higher depths. By changing proton energy one changes proton range. It helps to reach a high precision and to decrease dose to healthy organs.

In 2011 Poland joined an exclusive club over a dozen of countries having access to proton therapy.

The first treatment has been performed with the use of AIC-144 cyclotron developed at IFJ PAN. It delivers 60 MeV proton beam with range in water of 30 mm which is sufficient to treat eye tumours. On this facility 126 patients of Kraków University Hospital with eye melanoma were treated between 2011-2015.

With the strong support from Polish nuclear physicists the new Cyclotron Centre Bronowice (CCB) with Proteus-235 cyclotron was founded from the structural funds of European Union.

It provides 230 MeV protons having range of 320 mm in water, sufficient to reach tumour at an arbitrary depth in the body.

The beam is transported by vacuum ion guides to experimental hall, eye treatment room and two therapeutic gantries.

Gantry is the huge 11 meters in diameter, 120 ton construction on which the ion guides and focusing magnets are hanging on. Rotation of the gantry enables to deliver the beam to the patient from arbitrary direction with the precision of 1 mm. The scanning beam is systematically moving in the target: point after point, layer after layer. During the single fraction patient can be irradiated even by a few thousands of such mini-beams which leads to high precision even for complicated targets. Before irradiation a treatment plan is prepared. Computed tomography delivers a 3D map of the patient electron density which allows for selection of the optimal beam directions. During multistage dosimetric control medical physicists measure position, size and intensity of the beam to assure treatment precision.

During multistage dosimetric control medical physicists measure position, size and intensity of the beam to assure treatment precision.

Cyclotron and therapy systems are fully operated and serviced by physicists, engineers and technicians from IFJ PAN. Nowadays, about 20 patients are irradiated every day.

The proton radiotherapy methods were implemented for treatment of Polish patients in close collaboration of physicists from Poland, United Kingdom, Austria, Czech Republic, France, Germany, Italy, Russia, Sweden and USA. In CCB international experiments from nuclear physics, medical physics and radiobiology are carried on. Foreign researchers, who do not have access to such facility in their countries, use CCB in frame of TransNational Access financed from Horizon 2020 projects. The knowledge of physicists offered Polish physicians the great tool to fight cancer.