New spatially structured irradiation methodologies for radiotherapy are currently being developed, allowing for the sparing of healthy tissues while maintaining good efficacy against the tumor. We recently proposed a new compartmental model of cell population evolution after irradiation, which allows us to identify the different cell populations present (damaged, repaired, senescent cells, etc.) and which has shown that the fraction of surviving cells after irradiation in 2D depends on the initial cell density, a factor not taken into account by the linear-quadratic model [1]. To better understand what happens during irradiation, we now wish to study the tracking of individual cells, and this is the focus of this internship proposal. This project combines experiments, image analysis, and modeling: - Experimental part: cell culture, using a videomicroscope to track individual cells for four days. The cells will be irradiated with different doses (by permanent staff). - Image analysis will generate quantitative data on trajectories, the number of mitoses, survival, migration speed, cell-cell contacts, etc. - Finally, based on the data, a discrete stochastic agent-centered model will be developed to test scenarios, explain, and reproduce the obtained data. If possible, the continuous limit of this discrete model will be calculated and compared to the existing continuous model [1].