In November 2015, the proton therapy complex “Prometheus”, developed at PTC LPI RAS, started being used for the clinical treatment of patients with head and neck cancer. This complex consists of a...

The early delayed effects of accelerated carbon ions and protons on the cognitive functions of mice using tests of the total activity, spatial learning, and long-term and short-term hippocampal-dependent memory were studied. The obtained results showed that irradiated animals do not develop an altered behavioral pattern: the level of anxiety is not increased, the exploratory model of behavior is clearly pronounced, and there is no deficiency of hippocampal-dependent memory. However, the long-term memory test revealed fewer errors in finding an escape box in a group of animals irradiated with protons compared to the control animals and mice irradiated with carbon ions. The results may indicate a better preservation of memory traces under these conditions.

The aim of this work was to study the effect of proton pencil beam scanning in the Bragg peak in the dose range of 0.1–1.5 Gy on the induction of cytogenetic damage in the bone marrow, reactive oxygen species (ROS) production in whole blood, and the state of lymphoid organs after total body irradiation of mice. Irradiation was carried out in the Prometeus proton synchrotron (Protvino) in the Bragg peak with proton energy at the output of 90–116 MeV. It was found that, under irradiation of mice in the range of low and medium doses of proton pencil beam scanning in the Bragg peak, the relative biological effectiveness (RBE) according to the criterion of cytogenetic changes was 1.15. In addition, it was found that the pathophysiological effect on the lymphoid organs and the production of ROS by blood cells were different as compared with the effect of X-rays.

The combined effect of the irradiation with a proton pencil scanning beam (PBS) at a total dose of 80 Gy and neutron radiation at a dose of 5 Gy on the growth of solid Ehrlich ascites carcinoma (EAC) and the remote effects in tumor-bearing mice was studied. Combined irradiation of mice with neutrons before and after irradiation with PBS, as well as irradiation only with PBS, effectively suppressed the growth of solid EAC within 1 month. In terms of the frequency and severity of radiation-induced skin reactions of mice observed 15–40 days after therapy, neutron irradiation after the irradiation with PBS showed better values of these parameters as compared to only PBS; however, exposure to neutrons before PBS was more damaging as compared to the other two options. It was also shown that the tumor relapse rate in the groups of animals with combined irradiation was higher, and the total lifespan was lower than the group of mice irradiated with PBS alone.