Mevion Medical Systems Announces CE Marking of the MEVION S250-FIT™ Proton Therapy System, Expanding Global Access to Compact Proton Therapy

CE Marking enables marketing and clinical use of the world’s first and only LINAC vault-ready proton therapy system across the European Union

LITTLETON, Mass.--(BUSINESS WIRE)--Mevion Medical Systems, the global leader in compact proton therapy, today announced that the MEVION S250-FIT Proton Therapy System has successfully completed the conformity assessment process and has received CE Marking under Regulation (EU) 2017/745 (EU MDR). This regulatory milestone enables the marketing, sale, and clinical use of the MEVION S250-FIT system throughout the European Union, building on the system’s existing U.S. FDA 510(k) clearance granted in September 2025.

The MEVION S250-FIT is the first and only proton therapy system designed to fit into a standard radiation therapy vault. By enabling cancer centers to use their existing infrastructure, the MEVION S250-FIT dramatically reduces the cost, complexity, and timeline traditionally associated with proton therapy adoption. This opens a new pathway for hospitals and cancer centers across Europe to bring advanced proton treatment to their patients.

“With both FDA clearance and CE Marking now in hand, the MEVION S250-FIT is positioned to transform how proton therapy is delivered worldwide,” said Tina Yu, Ph.D., CEO and President of Mevion Medical Systems. “For European health systems that have long recognized the clinical benefits of proton therapy but faced significant infrastructure and financial barriers, the S250-FIT offers a fundamentally new approach, one that brings high-quality proton therapy directly into existing treatment environments. This is a defining moment for accessible cancer care in Europe and beyond.”

Advanced Clinical Capabilities in a Compact Footprint

The MEVION S250-FIT system features Mevion’s HYPERSCAN® pencil beam scanning platform for Intensity Modulated Proton Therapy (IMPT), delivering highly conformal dose distributions with hyper-fast energy layer switching and the Adaptive Aperture® proton multi-leaf collimator (pMLC).

The MEVION S250-FIT platform is designed to support DirectARC™ proton arc therapy, enabling VMAT-like speed and efficiency in proton treatment delivery.

The system incorporates a large-bore diagnostic CT aligned to the isocenter, enabling advanced image-guided radiation therapy (IGRT) and adaptive treatment workflows. An upright patient positioning system from Leo Cancer Care enhances flexibility in patient setup and enables treatment positions that may offer clinical advantages for select tumor sites. The platform is also FLASH research ready^*.

Building on Strong Global Momentum

The CE Mark follows the growing adoption of the MEVION S250-FIT platform. Mevion has signed contracts with nine leading institutions globally and announced installations and partnerships with major medical centers, including Stanford Health Care, BayCare Health System, Atlantic Health System, University of Nebraska Medical Center, Loma Linda University Health, and UNC Health.

The MEVION S250-FIT architecture also builds on the proven foundation of the MEVION S250i® platform, which has been operational at ZON-PTC at Maastro Clinic in the Netherlands, since 2018.

With CE Mark, European cancer centers and health systems can now evaluate the MEVION S250-FIT as a practical and cost-effective pathway to establishing or expanding proton therapy programs, without the need for purpose-built bunker construction or multi-year capital projects.

*For research use only and requires additional evaluation prior to use.

About Mevion Medical Systems

Mevion Medical Systems is the leading provider of compact proton therapy systems for cancer care. Dedicated to advancing the design and accessibility of proton therapy worldwide, Mevion pioneered the single-room platform and continues to further the science and application of proton therapy. Since 2013, Mevion compact proton therapy single-room systems have been used by leading cancer centers for treating patients. Mevion’s series of products, including the flagship MEVION S250i and MEVION S250-FIT™ with HYPERSCAN pencil beam scanning, represent the world’s most compact proton therapy systems that eliminate the obstacles of size, complexity, and cost. Mevion is headquartered in Littleton, Massachusetts with a presence in Europe and Asia. For more information, please visit www.mevion.com.