In a world’s first, physicians at Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine in St. Louis have begun treating patients using MRI-guided radiation therapy, a technology that allows tumors to be visualized during treatment.
Magnetic resonance imaging and radiation therapy have been used separately for decades to treat people with cancer. Until now, the technologies had not been integrated to provide real-time monitoring of tumors during treatment. Even if patients remain still, their breathing and the subtle movement of organs in the body can slightly skew the beams of radiation.
“Now we know precisely when a tumor shifts,” said Dennis Hallahan, MD, chairman of radiation oncology and the Elizabeth H. and James S. McDonnell III Distinguished Professor in Medicine. “This allows us to pause radiation with the goal of sparing healthy tissue, reducing side effects and improving a patient’s overall outcome. It’s one more advance in personalized cancer care.”
Radiation therapy is critical in the fight against cancer, and nearly two-thirds of patients receive radiation during their illnesses. Unlike other radiation therapy systems that rely on static images taken before or after treatment sessions, the new system uses real-time magnetic resonance images during radiation treatment to continuously track a tumor’s location. The technology is similar to the intraoperative MRI system that neurosurgeons at a handful of centers, including Barnes-Jewish Hospital, use to obtain real-time images during delicate surgery.
Two lung cancer patients, ages 67 and 80, were the first to undergo radiation therapy with the new system.
“Before, we didn’t have the ability to know precisely what was happening during radiation treatment,” said Sasa Mutic, PhD, director of medical physics and professor of radiation oncology. “We now can answer questions we never could before.”
Washington University radiation oncologists and physicists have been instrumental in developing the MRI-guided system, which involved conducting clinical trials and which the U.S. Food and Drug Administration approved for use in 2012. The technology especially will be useful for treating cancer in the abdomen or pelvis, where other current imaging doesn’t allow physicians to see clearly, said radiation oncologist Parag Parikh, MD, who led the clinical trials.
“The majority of tumors we treat are in soft tissue,” he said. “With this new technology, we not only can see exactly what we are treating, but we also can see subtle changes in the tumor that might call for changes to the radiation treatment plan.”
Siteman Director Timothy Eberlein, MD, the Bixby Professor and Spencer T. and Ann W. Olin Distinguished Professor, said offering this innovative technology reflects the cancer center’s goal of advancing patient care through clinical research and physician expertise.
“We are constantly working to provide the best care possible,” he said. “We do this in many ways, including using innovative technologies that offer better, less toxic treatment options to our patients.”
The radiation therapy system was developed and manufactured by ViewRay Inc., a privately held medical device company based in Bedford, Ohio. Jim Dempsey, PhD, a physicist who trained at Washington University, developed the technology and turned it over to Washington University radiation oncologists at Siteman for further testing and the development of treatment protocols.