ViewRay (Oakwood Village, Ohio) has received CE Mark approval for its MRIdian system, an MRI-guided radiation therapy system. The system previously received FDA approval in 2012, and is still the only such system available on the market.

The MRIdian system combines MR imaging with radiation therapy to visualise the location where radiation is delivered in real-time during treatment. The software can track tumor tissue in order to only allow treatment when the target is in range. Other such systems exist based on CT or X-ray technology, however these systems have the disadvantage of introducing an additional radiation dose and not being able to visualize the tumor in real-time.

The MRIdian is primarily intended for treatment of tumors that are likely to move significantly during treatment. This includes thoracic, abdominal and pelvic malignancies, such as lung, prostate, liver, and head and neck cancer.

source:ViewRay