Researchers at the University of Michigan Comprehensive Cancer Center developed the assessment, which they call a functional diffusion map. They used a magnetic resonance imaging scan that tracks the diffusion, or movement, of water through the brain and mapped the changes in diffusion from the start of therapy to three weeks later. The tumor cells restrict the movement of water, so as those cells die, water diffusion changes.
In the study of 34 people with a type of brain tumor called high grade glioma, the researchers found that they could predict after three weeks, based on the functional diffusion map, which cancers would respond to the treatment and which cancers would continue to grow. These predictions corresponded to a significant difference in how long the patients lived.
Results of the study appear the week of Oct. 31 in the early online edition of the Proceedings of the National Academy of Sciences.
High grade gliomas have a high mortality rate, with people surviving only an average of 12 months after diagnosis. Typically, patients receive six to seven weeks of treatment, followed by a traditional MRI scan six weeks after completing therapy to determine if the tumor shrank. If the cancer did not respond to the treatment, a new approach may be tried.
"An early measure of tumor response such as this functional diffusion map could help doctors identify during the course of treatment who might benefit from a second-line therapy, sparing patients from a grueling treatment regimen that's