ABSTRACT
The aim of clinical radiation therapy is to destroy neoplastic cells while the structural integrity of normal tissues is maintained. The overall time of irradiation and the number of fractions delivered are also important factors in most forms of clinical radiation therapy. A Neutrons, protons, helium-ions, pions, and heavy ions are all particles currently being considered for clinical radiation therapy. The physical advantages of charged-particle beams all result from the fact that they have a charge and include: Protons and helium ions provide the best physical dose distributions, followed by carbon and neon ions. Although argon ions have a less favorable physical dose distribution than other charged particle beams, they may be of interest clinically for relatively superficial, hypoxic tumors because of their low OER. While this type of clinical use will become available in the near future for neutron radiation therapy, it does not yet exist for charged-particle radiation therapy.
