Mevion Medical Systems said it has delivered a 15-ton compact accelerator to Mercy Hospital St. Louis in Missouri.
The accelerator will serve as the core of a Mevion S250i proton therapy system that is being installed at the David C. Pratt Cancer Center at Mercy St. Louis, according to the vendor.
![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)
