Kinetics of growth inhibition in a neoplastic population after repeated cytostatic treatment.

The analysis of growth kinetics of a neoplastic population after cytostatic treatment (radiation, chemotherapy) has been modeled by means of the cell cycle transition probabilities mu and transition intensities lambda. The transition between phases of the cell cycle and quiescent G0 cells during repeated cytostatic treatment has been exposed by the probabilistic model on the basis of the experimental data. The cytostatic treatment (the most effective time, dose and therapeutic combination) can be scheduled using established size and volume of the tumor and an estimate of cell proportion in various compartments of the neoplastic population. The probabilistic model has been worked out with the object of repeated cytostatic treatments in the optimum time with respect to the reduction of resistant quiescent G0 population. By repeating treatment in these times, the G0 population may be effectively reduced, the tumor is loosing its proliferation (recovery) potential and the further tumor growth may be for a long time delayed or even ceased.