ViewRay earned an FDA nod for its MRIdian Linac system, the first device to hit the market that combines MRI guidance with linear accelerator radiation. It allows physicians to visualize in real time the movement of tumors and organs during radiation treatment.
The new clearance brings MRI guidance to linear accelerator radiation, which is more common than the cobalt-60 therapy delivered by ViewRay's first-gen MRI-guided MRIdian system. It earned FDA clearance in 2012 and a CE mark in 2014.
Radiation therapy is traditionally done in two steps: First, the radiation oncologist uses imaging, usually a CT scan, to visualize the tumor and its surrounding area. While CT scans are the norm, MRI, ultrasound and PET scans may also be used, according to the National Cancer Institute. Once the physician has planned where to deliver radiation and in what dose, he or she will start treatment.
Combining these two steps allows the radiation oncologist to see the effects of radiation on the body during the procedure, said Benjamin Movsas, M.D., chairman of radiation oncology at the Henry Ford Cancer Institute in Michigan, in a statement. The physician may make changes to the way therapy is being delivered to “ensure the radiation continually remains on target,” he said.
The MRIdian Linac system may be used for treatment planning as well as during radiation procedures. It uses magnetic resonance imaging to differentiate between types of soft tissue and delivers more radiation to the tumor and less to the surrounding tissue.
“This technology helps us treat tumors such those in the lung, liver and pancreas where increased precision is important due to nearby organs and other critical structures,” said Sasa Mutic, director of radiation oncology physics at Washington University School of Medicine, in the statement.
ViewRay isn’t the only player combining imaging with radiation therapy. Hayward, California-based RefleXion Medical is working on a system that uses PET imaging to guide radiation therapy in real time. Because its tech is able to treat multiple tumors in parallel, RefleXion wants to make radiation therapy an option for cancer that has metastasized, which can currently only be treated using drugs.