Heavy-ion cancer therapy

The HIMAC Heavy-Ion Medical Accelerator in Chiba was completed in 1993, and clinical trials of particle radiotherapy for cancer were started using carbon beams accelerated by HIMAC in 1994. Since then, about 2200 patients have been treated in the carbon radiotherapy up to the end of February 2005. A heavy-ion beam generates a Bragg peak in a medium, and it provides biological effects of high RBE and low OER in the Bragg peak region. In heavy-ion radiotherapy, therefore, the beam delivers a high radiation dose to a target volume highly locally. These are excellent advantages for radiotherapy over the case of X-rays. The clinical trials have proved that carbon radiotherapy brings various good results.