ATLANTA Sept. 23, 2013. Protecting the stem cells that reside in and around the hippocampus a C-shaped area in the temporal lobe on both sides of the brain associated with the ability to form and store memories substantially reduces the rate of cancer patients' memory loss during whole-brain radiotherapy without a significant risk of recurrence in that area of the brain, a new study shows. Results of the Phase II clinical trial of patients with brain metastases are being presented today at the American Society for Radiation Oncology (ASTRO) annual meeting.
"Memory loss, especially short-term recall, is an important consideration for patients receiving whole-brain radiotherapy," says the study's co-principal investigator, Minesh P. Mehta, M.B., Ch.B., professor of radiation oncology at the University of Maryland School of Medicine. "We found that reducing the radiation dose to the stem-cell niches surrounding the hippocampus during treatment was clearly associated with memory preservation without an inordinate risk of relapse in that portion of the brain. The findings far exceeded our expectations."
Based on previous research, the predicted rate of cognitive decline at four months for patients receiving whole-brain radiation for brain metastases was 30 percent. Researchers designed the clinical trial so that a positive result would be a rate reduced by half, to 15 percent. The observed rate in the trial was actually 7 percent significantly better than the baseline rate of 30 percent. With a third fewer patients to evaluate, the rate of decline observed at six months was 2 percent, although comparable data from the historic control study were not available.
"These Phase II results, while not absolutely conclusive, offer very important insights which we hope to validate in a larger, randomized Phase III clinical trial," says Dr. Mehta, a radiation oncologist at the University of Maryland Marlene and Stewart Greenebaum Cancer Center
|Contact: Karen Warmkessel|
University of Maryland Medical Center