Saving Memories During Cancer Therapy

Brain radiotherapy that avoids the hippocampus may limit memory loss

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) When cancer spreads to the brain, radiation therapy is the treatment of choice. The whole brain is treated with radiation. And while this treatment prolongs life, mental function is affected. A new study looked at a technique that may save memories.

The hippocampus is the area of the brain that processes information to form short- and long-term memories.

Researchers found that limiting the amount of radiation to the hippocampus during whole brain radiotherapy may preserve cancer patients' memory function for months.

The technique prevented a significant amount of memory loss that patients usually experience following whole brain radiation.

"Ask your doctor about side effects you may experience from cancer therapy."

This study was directed by Vinai Gondi, MD, co-director of the Cadence Brain Tumor Center, associate director of Research at the Cadence Proton Center in Warrenville, Illinois and clinical assistant professor at the University of Wisconsin School of Medicine and Public Health in Madison, Wisconsin.

Between 2011 and 2013, 113 adult patients with brain metastasis (cancer which has spread) were recruited, and 100 individuals were analyzed for this study.

The patients received what’s called hippocampal avoidance whole-brain radiotherapy.

The radiation dose to the whole brain was 30 units (30 Gy in 10 fractions), while the dose to the entire hippocampus did not exceed 10 units (10 Gy), with a maximum dose of 17 units (17 Gy).

Participants were given cognitive and memory tests before treatment began and then two, four and six months after the radiotherapy.

Four months after the radiation treatment, the 42 participants who were tested showed a 7 percent decline in delayed recall.

This decline is significantly less than the 30 percent drop in delayed recall typically experienced by patients undergoing whole brain radiation therapy.

At six months, the decline was only an additional 2 percent.

Median survival for the group was 6.8 months.

Keith L. Black, MD, chair and professor of Cedars-Sinai’s Department of Neurosurgery, director of the Cochran Brain Tumor Center, director of the Maxine Dunitz Neurosurgical Institute and the Ruth and Lawrence Harvey Chair in Neuroscience, told dailyRx News, “This study confirms what one would predict, that limiting the radiation dose in areas that are critical for memory would result in improved cognitive and memory performance in patients.

"This is a comparison study with historical controls, which has limitations, but it nevertheless provides important clinical evidence of a beneficial effect of this approach,” Dr. Black said.

This study was presented at the American Society for Radiation Oncology’s (ASTRO’s) 55th Annual Meeting. 

All research is considered preliminary before it’s published in a peer-reviewed journal.

The National Cancer Institute funded this research. Two of the authors reported financial relationships with pharmaceutical and medical device companies.

Review Date: 
September 25, 2013
Last Updated:
December 30, 2013