Mevion Medical Systems will be upgrading a Mevion S250 proton therapy system installed at a site in Washington University School of Medicine in St. Louis, MO.
Mevision will add its Hyperscan pencil-beam scanning and Flash technologies to a system installed at the S. Lee Kling Proton Therapy Center at Siteman Cancer Center, Barnes-Jewish Hospital and Washington University
The purchase agreement with Barnes-Jewish Hospital was signed in December 2020 and the site received certificate-of-need approval in March. Company leaders say the upgraded system, now called Mevion S250i, is scheduled to be put into service in 2022.
![A 53-year-old patient (patient number four) with a recurrent pituitary adenoma with extension of a cystic component of disease to the medial temporal lobe apparent on MRI (contoured in blue), and extension of disease to the left sphenoid bone and orbital apex apparent on [68Ga]Ga-DOTA-TATE (contoured in yellow).](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/04/pituitary-tumor.QGsEnyB4bU.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
