Mevion Medical Systems has received CE Marking under Regulation (EU) 2017/745 (EU MDR) for its MEVION S250-FIT Proton Therapy System, marking a major regulatory milestone for the company. The approval allows the system to be marketed, sold and used clinically across the European Union. The development follows the system’s US FDA 510(k) clearance granted in September 2025.
The MEVION S250-FIT is described as the world’s first and only LINAC vault-ready proton therapy system. It is specifically engineered to fit into a standard radiation therapy vault, enabling hospitals and cancer centres to leverage existing infrastructure rather than construct purpose-built proton therapy facilities. This design significantly reduces the cost, complexity and timeline traditionally associated with adopting proton therapy.
Company leadership stated that obtaining both US FDA clearance and CE Marking positions the platform to expand global access to advanced proton therapy. For European healthcare systems that recognise the clinical benefits of proton therapy but have faced infrastructure and capital barriers, the S250-FIT offers an alternative pathway to integration within existing treatment environments.
The system incorporates Mevion’s HYPERSCAN pencil beam scanning platform for Intensity Modulated Proton Therapy (IMPT), providing highly conformal dose delivery with rapid energy layer switching and an Adaptive Aperture proton multi-leaf collimator. The platform is also designed to support DirectARC proton arc therapy, enabling treatment speeds and efficiencies comparable to VMAT-based photon therapy.
Advanced imaging capabilities are integrated into the system, including a large-bore diagnostic CT aligned to the isocenter for image-guided radiation therapy and adaptive workflows. An upright patient positioning system developed by Leo Cancer Care enhances flexibility in patient setup and may offer clinical advantages for certain tumour sites. The platform is also FLASH research ready.
The CE approval comes amid growing global adoption of the MEVION S250-FIT platform. Mevion has signed agreements with nine leading institutions worldwide and announced partnerships and installations with major medical centres, including Stanford Health Care, BayCare Health System, Atlantic Health System, University of Nebraska Medical Center, Loma Linda University Health and UNC Health.
The S250-FIT architecture builds on the foundation of the MEVION S250i platform, which has been operational at ZON-PTC at Maastro Clinic in the Netherlands since 2018.
With CE Marking now secured, European cancer centres can evaluate the MEVION S250-FIT as a practical and cost-effective route to establishing or expanding proton therapy programmes without undertaking multi-year construction projects or dedicated bunker development.
Mevion Medical Systems is a global provider of compact proton therapy solutions and pioneered the single-room proton therapy platform. Since 2013, its systems have been used by leading cancer centres worldwide to deliver advanced proton treatment to patients.
