Researchers have developed a new approach for brain imaging that can better distinguish immune responses from tumor growth in people with glioblastoma. The findings were published in Proceedings of the National Academy of Sciences.

With current imaging techniques, the inflammation that sometimes results from immunotherapies can resemble neurologic decline and tumor growth. But the new technique combines advanced magnetic resonance imaging, which offers enhanced anatomical resolution, with positron-emission tomography functional imaging, which detects the dCK enzyme in immune cells. Elevated dCK indicates that the tumor is responding to immunotherapy.

The study is ongoing and has been tested in mice and three people with recurrent glioblastomas. One patient received bevacizumab, which changed the appearance of the brain tumor on imaging, so the researchers say the new technique is more effective when bevacizumab is not used.