Learning How to Protect Thinking

Brain cancer toxicity maps help spare patient cognitive function

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) The brain is unlike any other organ in the body. Every area of the brain affects a major part of human life. Researchers are finding ways to protect cognitive function during brain cancer surgery.

Scientists have developed a “toxicity map” of the brain. This map indicates the maximum amount of radiation specific parts of the brain can receive without damaging cognitive function.  

Cognitive function has to do with how our minds work, how well we remember, figure out things, make decisions and so forth.  

"Research how tissue and organs are protected during radiation therapy."

Ann M. Peiffer, PhD, assistant professor of radiation oncology at Wake Forest Baptist in Winston Salem, NC, and colleagues analyzed the impact radiation treatments had on different parts of the brain.

Authors pointed out that physicians know exactly how much radiation can be given before affecting the function of organs such as the lungs, kidneys or liver.

These standards aren’t available for brain tissue.

The goal of this study was to define radiation doses that would be effective against the cancer without affecting cognition. To do this, the scientists looked at how radiation treatment impacts various areas of the brain.

The researchers came up with what they called a “toxicity map” that indicated the maximum radiation dosages for various parts of the brain. Delivery of higher dosages could result in damaging cognitive function.

“The issue is the toxicity to the brain and its function, which is cognition or how you think, and these functions are affected at a much lower dose of radiation than what causes tissue death,” Peiffer said.

Researchers looked at information about 57 brain cancer survivors who had received radiation therapy six or more months earlier. These individuals were taking part in another study that was evaluating if Aricept (donepezil) could help with their cognition.

Aricept is given to patients with Alzheimer’s disease.

Study members took cognition tests upon enrollment, and this information provided a look at cognitive function of various parts of the brain. The researchers then looked at patient records to determine how much radiation each participant received in the regions of interest.

“By matching cognitive performance to these measurements, we determined which area of the brain and what dose influenced performance on the cognitive tasks,” Dr. Peiffer said in a press release. “This gave us a preliminary look at what areas are important to consider for protecting cognition during our planning for radiation treatment.”

Then looking at the radiation doses given to specific areas of the brain, maximum tolerance levels to maintain function can be established, according to the researchers.

The authors said that additional research is needed to confirm these results.

These findings were reported in the February issue of the journal Neurology. The research was supported by the National Institutes of Health and by Wake Forest School of Medicine Medical Student Research Program, Louis Argenta Physician-Scientist Scholarship Fund, and the Department of Radiation Oncology.

Reviewed by: 
Review Date: 
March 27, 2013
Last Updated:
August 15, 2013