Mevion has launched a new proton therapy system called S250-Fit that can fit in existing linac vaults for better accessibility and affordability.
S250-Fit features Mevion's Hyperscan pencil beam scanning for intensity modulated proton therapy (IMPT), dual-energy large bore diagnostic CT at treatment position for image-guided radiotherapy (IGRT) and adaptive therapy, and Flash research capabilities. It is also designed to support access to emerging technologies like volumetric modulated arc therapy (VMAT).
Mevion is developing the system in partnership with Leo Cancer Care, a medical device company based in Middleton, WI, it said.
![Images show the pectoralis muscles of a healthy male individual who never smoked (age, 66 years; height, 178 cm; body mass index [BMI, calculated as weight in kilograms divided by height in meters squared], 28.4; number of cigarette pack-years, 0; forced expiratory volume in 1 second [FEV1], 97.6% predicted; FEV1: forced vital capacity [FVC] ratio, 0.71; pectoralis muscle area [PMA], 59.4 cm2; pectoralis muscle volume [PMV], 764 cm3) and a male individual with a smoking history and chronic obstructive pulmonary disorder (COPD) (age, 66 years; height, 178 cm; BMI, 27.5; number of cigarette pack-years, 43.2, FEV1, 48% predicted; FEV1:FVC, 0.56; PMA, 35 cm2; PMV, 480.8 cm3) from the Canadian Cohort Obstructive Lung Disease (i.e., CanCOLD) study. The CT image is shown in the axial plane. The PMV is automatically extracted using the developed deep learning model and overlayed onto the lungs for visual clarity.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/03/genkin.25LqljVF0y.jpg?auto=format%2Ccompress&crop=focalpoint&dpr=2&fit=crop&h=167&q=70&w=250)
