Risks seem to outweigh whole-brain radiation's rewards
Whole brain radiation to treat cancer that has spread to the brain is associated with significantly worse cognitive function than radiosurgery, and should no longer be used after radiosurgery to kill the cancer, according to a study led by an MD Anderson researcher.
Paul Brown, M.D., professor of Radiation Oncology, presented the results at the annual American Society for Clinical Oncology meeting held recently in Chicago.
The North American study enrolled 213 patients — most with lung cancer that spread to the brain. Patients were randomized to receive either radiosurgery alone, or radiosurgery followed by whole brain radiation.
Participants underwent seven cognitive tests before treatment and at several intervals after treatment. Those treated with both approaches performed significantly worse three months later on tests involving immediate recall of words, delayed recall, and measures of verbal communication. Patients given both treatments also scored lower on a quality-of-life questionnaire. Median overall survival was 7.5 months for those receiving both treatments and 10.7 months for those on radiosurgery alone.
“While the more aggressive treatment was better at preventing recurrence of tumors in the brain, it didn’t extend survival,” Brown said.
The definitive findings show that the deleterious impact on cognitive function outweighs any benefit associated with whole brain radiation and tumor control, said Brown.
Whole brain radiation is typically administered in 10 20-minute treatments given over two weeks while radiosurgery, in which radiation is delivered in a powerful, focused beam, is a longer procedure given in a single day.
Whole brain radiation therapy’s side effects include hair loss, skin redness, dry mouth and fatigue. It is associated with significant interruptions in chemotherapy. In contrast, side effects associated with radiosurgery are minimal, and it’s generally not associated with significant interruptions in chemotherapy, said Brown.