St. Louis (AP) - Two lung cancer patients at Barnes-Jewish Hospital are the first to receive radiation therapy in a machine that allows for real-time clear imaging of their tumors.
Magnetic resonance imaging and X-rays have long been used to take pictures of tumors to help doctors target the cancerous cells during radiation therapy. The new ViewRay machine allows for the MRI and the radiation to be produced at the same time, giving doctors a visual of the tumor as they deliver the radiation beams.
Oncologists can also observe CT scans during radiation treatment, but the MRI delivers a clearer image and doesnâ€™t add an additional dose of radiation. Real-time MRI scanning is also used in delicate surgeries of the brain and spine.
The ViewRay machine was developed by a Washington University doctoral graduate, Jim Dempsey, who brought his invention back to his alma mater for a clinical trial in 2011. The university holds no patents or financial interests in ViewRay.
Through the clinical trial that enrolled 27 patients, doctors discovered that the machine was particularly useful for those with soft tissue tumors in the lungs and abdomen, said Dr. Parag Parikh, assistant professor of radiation oncology at Washington University.
Lung tumors can move during radiation therapy as the patient breathes. Tumors in the stomach or intestines can also move around as a result of the digestive process. The size of the tumor can also change during the three- to eight-week course of radiation therapy.
â€śRight now we donâ€™t have good ways to line up those patients because we canâ€™t see whatâ€™s going on,â€ť Parikh said.
Doctors say the ViewRay has a potential advantage over traditional radiation by delivering a more geographically precise dosage for tumors that move and change in size. But there is no evidence that the new machine provides better outcomes for patients. The machine was approved by the FDA in 2012 but the costs to insurers compared to other radiation therapies are not yet available. Cancer centers at the University of Wisconsin and UCLA have also purchased ViewRay systems.
The ViewRay is the second radiation technology to debut at Barnesâ€™ Siteman Cancer Center in recent months. A proton therapy machine opened in December, primarily for cancers of the head, neck and spine. The proton radiation beam targets the tumor tissue and stops there, potentially limiting damage to healthy surrounding tissue. The first pediatric patient, 6-year-old Charlie North of Oakland, Ill., will receive proton therapy this week for a brain tumor.
â€śThe proton is a sharper knife, the ViewRay is a better look into seeing where weâ€™re aiming the knife,â€ť Parikh said. â€śWe may have a better view of what changes are happening day to day or week to week and be more precise in what we can do with the radiation.â€ť
Parikh said the hospital will continue to partner with Dempsey and ViewRay to study the effectiveness of the treatment and possibly open more clinical trials.
â€śTo support an old graduate, it is a bit of a St. Louis success story,â€ť Parikh said.