Patients with "limited number of brain metastases" advised to forego whole brain radiation

NEW YORK (Reuters Health) - The neurocognitive effects of whole-brain radiation are so debilitating that researchers from the University of Texas M. D. Anderson Cancer Center in Houston called off a randomized trial that was evaluating its effects on learning and memory in patients with brain metastases.

In a report published online October 5 in The Lancet Oncology, the researchers advise that stereotactic radiosurgery alone is the preferred initial treatment for such patients.

Study subjects who received stereotactic radiosurgery plus whole-brain radiation had twice the risk of developing learning and memory problems compared to patients who received radiosurgery alone.

First author Dr Eric L Chang, of the University of Texas M. D. Anderson Cancer Center, Houston, noted in an email to Reuters Health, "Our study...provides the strongest evidence to date that lends support for giving radiosurgery alone with close clinical monitoring as the preferred treatment strategy for patients newly diagnosed with a limited number of brain metastases," he added.

In the randomized controlled trial, patients with one to three newly diagnosed brain metastases were treated with either radiosurgery plus whole-brain irradiation (28 patients) or radiosurgery alone (30 patients). The primary endpoint was objectively measured neurocognitive function.

At 4 months, the trial was stopped by the data monitoring committee due to a high probability (96%) that patients in the radiosurgery plus whole-brain irradiation arm were more likely than patients in the radiosurgery-only arm to show a significant decline in learning and memory (mean posterior probability of decline 52% vs 24%).

This difference persisted at 6 months, with a mean posterior probability of decline of 28% and 8%, respectively, the investigators report.

At 6 months, brain recurrence was more likely in the radiosurgery-only group than in the whole-brain irradiation group. At one year, freedom from CNS recurrence was 73% with radiosurgery plus whole-brain irradiation compared with only 27% with radiosurgery alone.

Despite the difference in recurrence favoring irradiation, the researchers do not believe this benefit outweighs the disadvantage.

They strongly caution that patients who opt for radiosurgery only must commit to close clinical monitoring afterward.

"Applicability of the findings," they emphasize in their report, "is dependent on the willingness of patients and their physicians to adhere to a schedule of close monitoring, having consistent access to high-quality MRI, having access to a neurosurgical team willing and able to perform salvage resections when indicated, and applying strict physics quality-assurance procedures for stereotactic radiosurgery."

"Our strategy," Dr. Chang added, "is consistent with the trend towards personalized medicine of tailoring therapies to the patient and their disease rather than apply a 'one size fits all' approach of giving whole brain radiation therapy to all patients with brain metastases."

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