Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
; Beijing Proton Sci & Technol Dev Ltd Co, Beijing 100856, Peoples R China
A scattering proton beam delivery system for conformal therapy and intensity modulated therapy is described. The beam is laterally spread out by a dual-ring doublescattering system and collimated by a program-controlled multileaf collimator and patient specific fixed collimators. The proton range is adjusted and modulated by a program controlled binary filter and ridge filters.