MRI-guided radiation therapy has been a topic of discussion for well over a decade. MD Buyline’s James Laskaris first reported on the development of the technology in our May 2006 Leading Edge Report and then again with MD Buyline’s Issues that Matter – Emerging Technologies for 2010-2011. However, it wasn’t until last year that it materialized into an available cancer treatment solution.
Receiving FDA 510(k) clearance in May 2012, ViewRay Inc. has developed a system that at first glance looks like your typical MRI scanner. However, hiding within is the system’s rotating gantry. This gantry, which is responsible for delivering the radiation treatment, consists of three Cobalt-60 teletherapy heads each equipped with their own set of multileaf collimators (MLC’s).
The system can support multiple treatment techniques including 3D conformal therapy, Intensity-Modulated Radiation Therapy (IMRT), Image Guided Radiation Therapy (IGRT), Stereotactic Radiosurgery (SRS) and Stereotactic Radiotherapy (SRT). ViewRay’s split-magnet MRI system not only provides a way for improved pre-treatment imaging without added radiation dose, but also allows for real-time gated therapy. The system is equipped with software that continuously tracks the soft-tissue MRI images and automatically controls the cobalt beam during treatments. When the tumor moves outside the treatment beams’ path, which occurs during normal body movements such as respiration or digestion, the beam shuts off to ensure that only the specified tumor volume is treated.
The Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine announced in August 2010 that they would be the first facility to install the ViewRay System. In January 2012 they began clinical research to assess the systems’ MRI image quality.
“When physicians can clearly see the target, we are better able to adapt the treatment to changes in the patient’s anatomy,” said ViewRay’s Chief Medical Officer Prabhakar Tripuraneni, MD, FACR, FASTRO in a 2012 press release. “By verifying the high quality of the ViewRay system’s images, the Siteman study establishes the potential value of MRI-guided radiation therapy.
The University of Wisconsin Carbone Cancer Center and UCLA Jonsson Comprehensive Cancer Center are also early adopters of ViewRay’s MR-guided therapy solution.
With the first patient treatment expected later this year, ViewRay has made great strides in the world of radiation therapy. Real-time image guidance without an added dose of radiation is unheard of in radiation oncology, until now. ViewRay is definitely a vendor to watch as their solution just may change radiation therapy as we know it.