Tumor therapy with heavy charged particles

The inverse depth dose profile i.e. the increase of the dose with penetrati on depth make heavy charged particles like protons and heavy ions an ideal tool for the radiotherapy of deep-seated tumors. For carbon ions this good dose profile is potentiated by an additional increase in the relative biolo gical effectiveness (RBE) towards the end of the particle range. The physic al and biological basis of the action of ion beams in cells and tissues is briefly reviewed and the variation of radiobiological effectiveness as func tion of the radiation quality will be explained, The different technical so lutions for the shaping of the radiation area according to the planned targ et volume are presented. The possibility to monitor in situ the area affect ed by the beam in the patient by means of positron emission tomography PET is illustrated, Different layouts of therapy units are compared for protons and carbon ions. Finally, the long way from the first proposal for a medic al application of ion beams to the current situation is summarized, Because of the clinical success of ion beam treatment all planned further centers are planned all over the world.