Scientists Probe Radiotherapy-Linked Brain Changes

TUESDAY, Nov. 7 (HealthDay News) -- Researchers believe certain brain changes may be linked to the dementia experienced by many cancer patients after whole-brain radiation treatment.

Each year, about 200,000 people in the United States receive whole-brain radiation, which is used to treat recurrent brain tumors as well as to prevent breast cancer, lung cancer, and malignant melanoma from spreading to the brain.

About a year after whole-brain radiation treatment, up to 50 percent of patients develop progressive learning and memory problems.

In their research with rats, a team at Wake Forest University School of Medicine in Winston-Salem, N.C., found that whole-brain radiation caused compositional changes in brain cell receptors for the neurotransmitter glutamate.

A neurotransmitter carries signals between brain nerve cells. The changes in these receptors appear to be associated with cognitive problems.

"By identifying exactly how radiation causes these side effects, our hope is that we can find a way to prevent or reverse them," study lead author and research fellow Lei Shi explained in a prepared statement.

The findings were presented Monday at the annual meeting of the Radiation Research Society, in Philadelphia.

"There is growing concern about the cognitive consequences of whole-brain radiation. Our findings suggest that very subtle changes may be critical and that glutamate receptors may be one of those changes," Wake Forest senior researcher Judy Brunso-Bechtold, professor of neurobiology and anatomy, said in a prepared statement.