Back to All News

World’s First MRIdian Center Treats 1,000th Patient with MRI-Guided Radiation Therapy

ViewRay MRIdian

CLEVELAND, May 22, 2019 — ViewRay, Inc. (Nasdaq: VRAY) announced today that the clinical team at Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine in St. Louis has treated its 1,000th patient using MRIdian MR-guided radiation therapy.

Siteman Cancer Center helped pioneer MR-guided radiation therapy, becoming the first center to treat patients with MRIdian in January 2014. Siteman also leads the industry as the first to perform adaptive radiation therapy under MR-guidance. MRIdian’s on-table adaptive capability and automated beam gating, now routinely practiced at Siteman, allows clinicians to personalize the radiation delivery by adapting to daily changes in a patient’s anatomy, while its real-time tissue tracking and beam control allow greater precision to the delivery of radiation therapy. As the use of MR-guided radiation therapy expanded, Siteman acquired a second MRIdian System – the MRIdian Linac – in November 2017, following FDA-clearance of this next-generation technology from ViewRay. The new technology features MRI-guidance combined with linear accelerator delivery.

“We commend the Siteman team for its continued adoption and advancement of innovative technology to further patient care, and congratulate them on reaching this exciting milestone,” said Scott Drake, President and Chief Executive Officer of ViewRay. “The center’s trailblazing research and cutting-edge treatments have played a big role in the clinical acceptance and growing adoption of MRI-guided radiation therapy, which, in turn, has benefitted not just the 1,000 cancer patients at Siteman but many others around the world.”

“The location of tumors in the body can fluctuate slightly in response to subtle movements, such as breathing, potentially disrupting the precise target of a radiation beam,” said Jeff Michalski, M.D., Carlos A. Perez Distinguished Professor, Vice Chair and Director of Clinical Programs in Radiation Oncology at Siteman Cancer Center and Washington University School of Medicine. “MR-guided radiation therapy allows us to visualize and precisely track the contours of a patient’s tumor as radiation therapy is being delivered. With this enhanced visibility, we can quickly adjust the dose of radiation in real time to account for changes in the position of a tumor. This capability helps to ensure that the maximum dose reaches the tumor and incidental exposure to surrounding healthy tissues is minimized.”

Clinicians and researchers at Siteman have been active in sharing their research and clinical experience to further the practice of MRI-guided radiation therapy. To date, the team has published nearly 40 manuscripts in peer-reviewed journals and presented data at more than 100 major medical meetings, highlighting its MRI-guided radiation therapy experience. At Siteman, MRI-guided radiation therapy is involved in the treatment of patients whose tumors lie near critical anatomical structures and is being evaluated in clinical trials for pancreas, breast and lung cancers.

About ViewRay

ViewRay®, Inc. (Nasdaq: VRAY), designs, manufactures and markets the MRIdian® radiation therapy

system. MRIdian is built upon a proprietary high-definition MR imaging system designed from the ground up to address the unique challenges and clinical workflow for advanced radiation oncology. Unlike MR systems used in diagnostic radiology, MRIdian’s high-definition MR was purposely built to deliver high-precision radiation without unnecessary beam distortion, and consequently, help to mitigate skin toxicity and other safety concerns that may otherwise arise when high magnetic fields interact with radiation beams. ViewRay and MRIdian are registered trademarks of ViewRay, Inc.

Intended Use: The MRIdian Linac System, with magnetic resonance imaging capabilities, is intended to provide stereotactic radiosurgery and precision radiotherapy for lesions, tumors, and conditions anywhere in the body where radiation treatment is indicated.

Forward Looking Statements: This press release contains forward-looking statements. Statements in this press release that are not purely historical are forward-looking statements. These statements are subject to risks and uncertainties that could cause future results to differ materially from those referenced. Forward-looking statements include, but are not limited to, statements about ViewRay’s financial results and market acceptance of ViewRay’s existing products, future products or technology. Words such as “could,” “anticipates,” “expects,” “outlook,” “intends,” “plans,” “believes,” “seeks,” “vision,” “estimates,” “may,” “will,” “future,” “horizon,” “aiming,” “driving,” “target” (or variations of them) and similar statements, are forward-looking statements. Forward-looking statements involve risks, uncertainties and assumptions that are difficult to predict and could cause ViewRay’s results to differ materially from those presented. These risks, uncertainties and assumptions include, but are not limited to, changes in: the regulatory environment; global economics; trade compliance requirements, duties or tariffs; third-party reimbursement levels; currency exchange rates; taxation, healthcare law, and product clearance requirements, as well as those related to: adverse publicity about ViewRay and our products; our reliance on sole or limited source suppliers; our ability to commercialize our products successfully; the impact of competitive products and pricing, and all other risks listed from time to time in the company’s filings with the Securities and Exchange Commission, available at, which are incorporated into this Forward-Looking Statements disclosure by this reference. These forward-looking statements are made as of the date of this press release, and ViewRay assumes no obligation to update the forward-looking statements, or to update the reasons why actual results differ from those projected in the forward-looking statements, except as required by law.

Update: ViewRay technology, including MRIdian, is no longer in use at Siteman Cancer Center or at any other cancer center. Washington University Physicians use other precision imaging products like HyperSight and Ethos in procedures.