[Experimental approaches in studying the biological properties and radiation sensitivity of human brain tumors].

The share of proliferating cells, the tumor growth fraction, was studied in 11 cases of glial tumors of the large hemispheres of man. The individual sensitivity of human glial tumors to irradiation was determined in 7 cases by the method of tumor growth in diffusion chambers. It was established that glioblastomas and dedifferentiated astrocytomas were characterized by a sufficiently high proliferative activity. The duration of the history of the disease and the period free of recurrences correlated with the value of the growth fraction in many cases. Gliomas, even of the same histostructure, differed considerably in the reaction to irradiation in some patients. The sensitivity of tumor cells to irradiation in growth in diffusion chambers does not depend on the proliferative activity of the initial tumors determined on operative material.