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Learn More About Proton Therapy
Learn More About Proton Therapy

Success Stories

Smart Medicine, Smart Business: Siteman Cancer Center

Siteman Cancer Center at Barnes-Jewish Hospital in St. Louis is a nationally recognized NCI Comprehensive Cancer Center of Excellence. The proton therapy facility was built underneath an existing parking garage in a space-constrained urban setting on the Barnes-Jewish Center for Advanced Medicine campus. The proton center was designed to take advantage of the proximity of the radiation therapy department across the street where imaging, planning, follow-up and professional staffing offices are located. Radiation therapy staff has direct access to the center from the existing radiation therapy department via an underground tunnel. The proton facility went live in December 2013 and was the world’s first compact proton therapy system.


The proton therapy center has two Mevion side-by-side treatment rooms, with one MEVION S250 fully installed and another that can be installed in the future.

Treatment Mix

The site treated 250 patients in its first two years, with a mix of 25% pediatric and 75% adult patients, including a wide variety of complex tumors:

44% - intracranial region

24% - lungs

10% - craniospinal region

7% - prostate

5% - head and neck

10% - other

Proven Results

In its first year, the site exceeded its business plan by 35%, delivering more than 6,700 clinical proton treatment fields to 118 patients. Since opening, the system has had a clinical uptime of more than 98% and it currently treats 25 patients per day in a 10 hour shift.