November 2, 2010 – A new proton therapy system is entering the final phase of installation at the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine in St. Louis, Mo.
The Monarch250, by Still River Systems, is an important treatment option for cancer patients, since it spares healthy tissue and results in fewer complications. The device houses a proton source based on the world’s first superconducting synchrocyclotron. It also provides a significant reduction in the size, cost and complexity of developing and operating a proton therapy center.
The system is installed in three phases in a radiation therapy room comparable to a conventional radiotherapy system. Phase 1 consists of rigging and mounting the accelerator gantry, which holds and positions the proton source. The second phase involves assembling and installing the clinical environment. The third and final phase consists of the installation of the accelerator module.
Bill Alvord, the institution’s vice president of operations, said the first and second phases take about two months to complete.
The production accelerator is now undergoing clinical commissioning, and all clinical parameters have exceeded performance expectations.
Still River Systems will be exhibiting at the American Society for Radiation Oncology (ASTRO) conference in San Diego, Calif. The Monarch250 has not been cleared by the U.S. Food and Drug Administration (FDA).
For more information: www.stillriversystems.com
September 30, 2025 
