Mevion Medical Systems, Inc.

Mevion Medical Systems is a radiation therapy company specializing in compact proton therapy systems for cancer treatment. Founded in 2004 and based in Littleton, Massachusetts, Mevion has raised $528.5 million in funding and maintains international offices in the United Kingdom and Japan. The company's flagship MEVION S250 Series comprises the MEVION S250 Proton Therapy System, MEVION S250i with advanced pencil beam scanning capabilities, and MEVION S250-FIT, designed for integration into existing radiation oncology departments. Mevion's systems are recognized for their compact design, which significantly reduces footprint, complexity, and capital/operating costs compared to conventional proton therapy equipment. The systems deliver 97–98% uptime and have achieved FDA clearance and CE marking. More NCI-Designated Cancer Centers select Mevion than any competing proton therapy vendor, reflecting strong clinical adoption and market leadership in particle therapy.