Mevion Medical Systems Receives FDA Clearance for Proton Beam Radiation Therapy System

Sept. 15, 2025 — Mevion Medical Systems  announced that the U.S. Food and Drug Administration (FDA) has granted 510(k) clearance for the MEVION S250-FIT Proton Beam Radiation Therapy System, marking a significant milestone in expanding access to proton therapy. 

The MEVION S250-FIT is the first proton therapy system designed to seamlessly fit into a standard radiation therapy vault. By leveraging existing infrastructure, the MEVION S250-FIT system lowers barriers for hospitals and cancer centers to adopt proton therapy, accelerating access and bringing advanced, high-quality proton therapy closer to patients worldwide.

The MEVION S250-FIT is currently under installation at Stanford Health Care and BayCare Health System, with additional installations beginning at Atlantic Health System and the University of Nebraska Medical Center. This momentum underscores how top-tier institutions are embracing the MEVION S250-FIT system as a future-ready, quality-driven solution, reaffirming Mevion’s role as the trusted partner of leading cancer centers.

“The FDA clearance of the MEVION S250-FIT marks the beginning of a new era in proton therapy. For more than two decades, Mevion has redefined proton therapy through audacious innovation -- from pioneering the world’s first compact, single-room system to now enabling proton therapy to fit into existing radiation therapy vaults, expanding access for patients worldwide. I am incredibly proud of the Mevion team and our partners at Leo Cancer Care for making this achievement possible and look forward to the impact of this innovation as centers like Stanford bring it to patients.” — Tina Yu, CEO and President of Mevion Medical Systems.

The MEVION S250-FIT system extends Mevion’s leadership in compact proton therapy by combining industry-leading precision, efficiency, and adaptability. Building on Mevion’s HYPERSCAN pencil beam scanning platform and introducing DirectArc proton arc therapy, the FIT system is also FLASH research ready, ensuring cancer centers gain advanced capabilities today while staying ready for future innovations.

For more information, please visit www.mevion.com.