The spatial distribution of positron-emitting nuclei generated by relativistic light ion beams in organic matter

The range distributions of positron emitters generated during the stopping process of relativistic light ions in organic matter exhibit a pronounced maximum near the range of the primary particles. The shape of this distribution can be qualitatively understood from a simple Monte Carlo approach of the stopping, fragmentation and decay processes. These results offer the possibility of beam monitoring by means of PET techniques during the tumour therapy with a light ion beam. Furthermore, a refinement of this technique may allow the actual dose distribution to be calculated from PET data.