The Development of Proton Radiotherapy in Our Country

Protons are the relatively heavy charged particles and therefore can be accelerated to any energy, permitting the long distance penetration in the human body practically without loss of the dose-rate. In addition, due to the low side scatter the use of these particles permits obtaining the better dose distribution between the tumor and the surrounding healthy tissues in comparison with the traditional sources of ionizing radiations. The limited clinical study of proton radiotherapy was initiated in early 1950th in USA and shortly afterwards in Sweden, and at the end of 1960th have started in USSR at two physical institutions located in Dubna and Moscow. Later the third institution — in Gatchina, the suburb of Leningrad, started treatment of tumors with the beams of accelerated protons. And to the end of 1980th the USSR has accumulated the largest experience in the world in using proton beams for treatment of patients with malignant and benign tumors as well as blood vessel malformations in brain. During last thirty years proton radiotherapy became widely used method in oncology, especially due to the shift from the use of huge physical installations to the specially designed ‘medical accelerators’ which are installed now in many medical institutions. The number of the treated patients grows to two hundred thousand, and now one of the main tasks is determination of those patients to whom this expensive type of radiotherapy could be the most efficient. This efficiency is evaluated either on the better results of tumor treatments or, which is especially important for proton radiotherapy, on the better sparing of normal tissue damage in comparison with the efficacy of tumor eradiation usual for other sources of radiation.