[DNA synthesis activity and growth fractions of brain tumors].

Histoautoradiographic and immunohistochemical studies of biopsies from 27 brain tumors yielded the following preliminary conclusions: 3H-thymidine labeling indices and Ki-67 growth fraction indicate the proliferative activity more reliable than counting of mitoses, the fraction of DNA synthesizing tumor cells and the Ki-67 growth fraction show an equal behaviour, as expected, the immunohistochemical values are higher than the labeling indices because all tumor cells within the proliferation cycles express the nuclear antigen. By the increase of the number of tumors and the use of the different cell kinetic methods on the same tumor tissue the prerequisite to grading of brain tumors as a basis of therapeutic strategy can be improved.