More than 4,000 children battle brain cancer every year — it's more common than leukemia. About 25% of the time, the cancer returns after treatment.

Seattle Children's is announcing a new study that seeks to stop cancer when it recurs.

The study is called Brain Child 01. It takes a different approach to immunotherapy, a treatment that uses the body's own cells to target cancer. This time, doctors plan to inject cancer-fighting CAR T-cells directly into the brain.

"We are using a newer generation of CAR T-cells with better signaling domains around it that will help the cell activate better," says Neurooncologist Dr. Nicholas Vitanza.

Dr. Vitanza moved to Seattle specifically to work on studies like this with Dr. Mike Jensen, Director of the Ben Towne Center for Childhood Cancer Research. They hope to show that using the brain’s enclosed barrier wall to keep the immunotherapy cells contained will increase the effectiveness of the already proven CAR T-cell therapy.

Typically, fighting pediatric brain cancer involves radiation and chemotherapy. Not only is the process incredibly hard for a child to endure but can also affect their long-term health.

This new study seeks to stop cancer at the source by putting the cells at the source.

“This is very exciting new technology. It's offering a new chance for a lot of people who thought they were out of chances. So we do have a lot of patients who are already interested and we've already begun screening some patients that will be able to help with this.”

Brain Child 01 will likely be the first of several trials surrounding this theory. Ultimately, if the study is successful, doctors would like to be able to use the treatment earlier so that children can avoid the side-effects of radiation and chemotherapy. Dr. Vitanza points out that kids with brain tumors who don’t get radiation experience have roughly half the survival rate of those who do. The Brain Child 01 study is now recruiting patients.