QUANTITATIVE DESCRIPTION OF PARTICLE INTERACTIONS WITH BIOLOGICAL SAMPLES

Single particle microbeam irradiation systems provide the tool needed to investigate the response of cells and some other biological systems to extremely low doses of high LET radiation. However, the resulting exposure, which consists of specified numbers of charged particles through specific portions of cells, cannot be described by conventional dosimetry concepts which were defined to characterise average energy depositions in a randomly irradiated population. In order to take advantage of the information provided by microbeam irradiation, it is important to describe the experimental irradiation in a way which can be correlated with the radiation interactions in individual cells in vivo which can be calculated for many radiation exposures. An approach, based on characterising the response as a function of both the particle stopping power and the path length through the cell or other defined target, is described.