Growth and spreading behaviour of tumours and metastases are still subject of intensive research regarding the most effective treatment intervention in individual cases. It is difficult to evaluate experimental data regarding different treatment strategies and its individual characteristics for their clinical relevance. Our collaboration developed a computer model which allows a quantitative comparison of effects of treatment interventions with clinical and experimental data.

The computer model is based on a discrete event simulation protocol. Analytical functions describe the growth of primary tumour and distant metastases, a rate function models the intravasation events of the primary tumour and its metastases. Events describe the behaviour of the emitted malignant cells until the formation of new metastases.

We analysed data from experiments with untreated groups of mice from human small cell lung cancer lines OH-1 and extracted information about the growing and spreading behaviour. On this basis we modelled experimental data from groups of mice, which were treated with chemotherapy and radiation therapy. Our results reveal that the fractal dimension of the primary tumour vasculature changes during treatment. That indicates that the therapy affects the blood vessels’ geometry. We proved that by quantitative histological analysis showing that the blood vessel density is depleted during treatment.