Biophysical and radiobiological aspects of heavy charged particles

Heavy-ion beams have unique biophysical and radiobiological properties, such as the inverted depth dose profile compared to photon beams, relative biological effectiveness and oxygen enhancement ratio. These physical and biological properties are much more favourable than those of photon radiotherapy and can be used to treat tumours efficiently. During a long-term stay in space, astronauts will be constantly exposed to low-dose space radiation. Thus, space radiation is one of the major health-related concerns for space exploration. This review summarizes the biophysical and biological properties of charged particles and their advantage in radiotherapy. In addition, we briefly reviewed the importance of the heavy ion during space flight and how to suppress its deleterious effects.