No, proton therapy is not an experimental or research method. It has been used in the USA in research centers for more than 50 years, and in hospitals - since 1990, that is, more than a quarter of a century. This is a generally acknowledged method adopted by a wide range of doctors, government agencies and insurance companies. The number of proton centers in the world is growing rapidly. According to forecasts, by 2018 their number will reach 88.