Whole brain radiation shown to be twice as likely to cause decline in neurocognitive function

50th ASTRO Annual Meeting

BOSTON — Researchers at M.D. Anderson Cancer Center have found that patients with one to three newly diagnosed brain metastases assigned to whole brain radiation were more than twice as likely to experience serious declines in brain function compared with patients assigned to radiosurgery alone.

Eric L. Chang, MD, an associate professor in the department of radiation oncology at M.D. Anderson, presented the results of a phase-3 trial at the American Society for Therapeutic Radiology and Oncology’s 50th Annual Meeting.

Chang said the mean probability of neurocognitive decline for patients assigned to radiosurgery and whole brain radiation therapy was 49% compared with 23% for those assigned to radiosurgery alone.

The researchers enrolled 58 patients with one to three newly diagnosed brain metastases. Thirty patients were randomly assigned to radiosurgery alone, and the rest were assigned to radiosurgery plus whole brain radiation.

After evaluating patients’ brain function using the Hopkins Verbal Learning Test Revised, the researchers found that those assigned to whole brain radiation had suffered serious declines.

“That’s the concern about administration of whole brain radiation therapy: it’s effect on patients thinking ability or neurocognition,” Chang told HemOnc Today. “Even though [these patients] have a limited life span, this study is showing that neurocognition is affected by the treatment moreso than the disease itself.”

The researchers were surprised to discover whole brain radiation also had a negative impact on survival. OS was 15.2 months for patients assigned to radiosurgery alone vs. 5.6 months for the whole brain radiation arm (P=.003). One-year survival was 61% for the radiosurgery arm compared with 19% for the whole brain therapy arm (P=.003).

“Based on the level 1 evidence presented today, radiosurgery alone coupled with close clinical monitoring could be considered the new standard of care for patients newly diagnosed with one to three brain metastases,” Chang said. – by Jason Harris

The somewhat alarming thing about the study is it shows that, to their surprise, whole brain radiation had cognitive effects that are profound enough that we have to weigh them against the benefits. The one thing that really stood out is this reminder that for everything we do, there are consequences. We have to be mindful of that. It’s a small study, but it really challenges the way we think about this disease.

– Anthony L. Zeitman, MD

Professor of radiation oncology at Harvard Medical School

For more information:

Chang EL. Phase-3 randomized clinical trial of radiosurgery with or without whole brain irridation in patients newly diagnosed with one to three metastases. Presented at: the American Society for Therapeutic Radiology and Oncology’s 50th Annual Meeting; Sept. 21-25, 2008; Boston.