Hadronic radiotherapy uses particle beams to treat tumors located near critical body structures and tumors that respond poorly to conventional photon and electron beam radiotherapy. Initial research in hadronic radiotherapy was performed using accelerators built for physics research. At present, there are a few hospital-based accelerators dedicated to this form of therapy. More are being constructed.This book presents the first comprehensive overview of the field with a discussion on the fundamental basis of particle physics and radiobiology, as well as review of clinical and technical specifications and solutions for proton radiotherapy. In particular, the current solutions of proton and heavy ion accelerators, beam delivery systems, gantries, beam monitoring and dosimetry systems, control and safety systems, patient positioning and immobilization devices, and ancillary treatment facilities are widely discussed.