Regularities of Induction and Growth of Tumors in Mice upon Irradiation of Ehrlich Carcinoma Cells ex vivo and in vivo with a Pencil Scanning Beam of Protons

Abstract

The patterns of tumor induction and growth in mice were studied under single irradiation with a proton beam at doses of 30, 60, and 80 Gy of Ehrlich carcinoma cells under ex vivo and in vivo conditions. It was shown that the frequency of tumor induction after proton irradiation of Ehrlich carcinoma cells ex vivo at a dose of 30 Gy was lower than after irradiation in vivo, and at doses of 60 Gy and 80 Gy, the number of tumors was the same. The temporal patterns of tumor occurrence during irradiation of Ehrlich carcinoma cells ex vivo differed significantly from in vivo irradiation: the period of time when the appearance of new tumors was recorded in the ex vivo groups was the same for all doses, and during in vivo irradiation it had a dose dependence. The growth rate of Ehrlich carcinoma tumors after cell irradiation ex vivo and in vivo did not depend on the dose, the method of irradiation, or the time of their occurrence, but was significantly lower than in the control group. The results obtained are of interest for understanding the mechanisms of manifestation of potentially lethal damage to tumor cells, the role of the tumor microenvironment in the induction of relapses and ways to overcome them using the potential of proton therapy, as well as for the development of biomedical models to search for optimal targets for hadron cancer therapy.