High Energy Cancer Care™ The confluence of elegance, precision, safety, and efficiency is defining the future of proton therapy. Mevion Medical Systems introduces the MEVION S250 Proton Therapy System. Designed to preserve all of the treatment benefits of conventional proton treatment systems, the MEVION S250 removes the obstacles of size, cost and complexity that have limited adoption of proton therapy. Precise, safe, efficient, and practical – the MEVION S250™ is a truly elegant solution that is making proton therapy readily accessible to the pediatric and adult cancer patients who can now benefit from the power of High Energy Cancer Care.