[Cell proliferation parameters in human rectal tumors and their transformation during fractionated irradiation]

Human rectal adenocarcinoma is characterized by considerable variation in labelling index for different tumors as well as different areas within the same tumor. Therefore, the averaged indices of tumor cell proliferative activity do not mirror the actual heterogeneity of tumor. Conventional schedules of fractionated irradiation resulted in a decreased labelling index and varying response in most cases under study. Following large-dosage fractionated irradiation, labelling index remained unchanged or showed a slight decrease. The rate of DNA synthesis is practically unaffected by the available schedules of fractionated irradiation.