Gantry optimization of the Shanghai Advanced Proton Therapy facility

A proton therapy system is a large medical device to treat tumors. Its gantry is of large structure and high precision. A new half-gantry was designed in the Shanghai Advanced Proton Therapy (SAPT) project. In this paper, the weight of gantry in design is reduced significantly by size and structure optimizations, to improve its cost-effectiveness, while guaranteeing the functions and precision. The processes of physics optimization, empirical design optimization, topological optimization and size optimization, together with factors of consideration, are described. The gantry weight is reduced by 30%, with the same precision. (authors)