New accelerator facility for carbon-ion cancer-therapy.

The first clinical trial with carbon beams generated from HIMAC was conducted in June 1994. The total number of patients treated as of December 2006 was in excess of 3,000. In view of the significant growth in the number of protocols, the Japanese government gave its approval for carbon-ion therapy at NIRS as an advanced medical technology in 2003. The impressive advances of carbon-ion therapy using HIMAC have been supported by high-reliability operation and by advanced developments of beam-delivery and accelerator technologies. Based on our ten years of experience with HIMAC, we recently proposed a new accelerator facility for cancer therapy with carbon ions for widespread use in Japan. The key technologies of the accelerator and beam-delivery systems for this proposed facility have been under development since April 2004, with the main thrust being focused on downsizing the facility for cost reduction. Based on the design and R&D studies for the proposed facility, its construction was begun at Gunma University in April 2006. In addition, our future plans for HIMAC also include the design of a new treatment facility. The design work has already been initiated, and will lead to the further development of therapy using HIMAC. The following descriptions give a summary account of the new accelerator facility for cancer therapy with carbon ions and of the new treatment facility at HIMAC.