Design of a compact superconducting accelerator for advanced heavy-ion therapy

Radiotherapy using energetic carbon beams from the Heavy Ion Medical Accelerator in Chiba (HIMAC) has been carried out at the National Institutes of Quantum Science and Technology (QST) since June 1994. Based on positive clinical results, carbon-ion radiotherapy was authorized as an Advanced Medical Technology by Japanese government from 2003 and it was subsequently approved for inclusion in the Japanese National Health Insurance system from 2016. For the widespread use of carbon-ion radiotherapy, design studies as well as related research and development projects were conducted to develop a compact accelerator facility from 2004. Based on these studies, five compact facilities were constructed in Japan. However, since the accelerators are large in size, construction of these facilities is currently limited to university hospitals or large medical centers, and hence development of a more compact accelerator is desired. To further promote widespread proliferation of heavy-ion facilities and concurrently to maximize the potential of heavy-ion therapy, a project to develop a compact superconducting accelerator, the Quantum Scalpel project, was proposed. The compact accelerator employs superconducting technology to reduce the footprint of the entire accelerator system and the accelerator can provide various therapeutic beams of helium, carbon, oxygen, and neon ions having the energy of 56-430 MeV/u to advanced heavy-ion therapy. In this article, we report the design of the compact superconducting accelerator for the advanced heavy-ion therapy and describe the progress of related research and development projects.