[Cell proliferation kinetics of solid tumors in childhood]

With the aim to develop an improved individual therapy of tumor-affected children, tumor particles were in vitro incubated with radioactively labeled precursors in order to determine the parameters of cell proliferation kinetics. The growth rate of the tumors was derived from the 3H-uridine labelling index. A "cell kinetic therapy index" is calculated from the temporal ratio of the cell cycle phases S, G2, and M, which are sensitive to cytostatic compounds and radiation, and of the mean duration of the cell cycle. When the cell kinetic therapy index (ZTI) is below 0.2 chemotherapy is scarcely promising whereas it is promising at 0.5 and above. The experimental data of Wilms tumors, osteogenic sarcomas and rapidly growing neuroblastomas are in good agreement with the clinical rate of tumor remission.