Whole Brain Radiation Not Best for Cancer That Has Spread

Sept. 24 -- TUESDAY, Sept. 23 (HealthDay News) -- The common practice of adding whole brain radiation to more focused radiation treatment for cancers that have spread to the brain not only caused greater learning and memory problems, but also was associated with a shorter survival time in a controlled study.

The survival time data should be approached with caution, because the primary purpose of the study was to help settle a debate about the effects of whole brain radiation on mental function, said study author Dr. Eric L. Chang, an associate professor of radiation oncology at M. D. Anderson Cancer Center in Houston. He presented the results Sept. 22 at the American Society for Therapeutic Radiology and Oncology annual meeting, in Boston.

But, he said, "this report will stimulate a lot of comment because of results we did not expect."

Opinions about the best treatment for cancers that start somewhere in the body and spread to the brain are divided, with some physicians using only stereotactic radiosurgery, which pinpoints radiation directly at the brain cancer colonies, and others adding whole brain radiation, Chang said.

"No one has been able to show that one treatment is better," he said. "It is up to patient preference, physician preference, the philosophy of the institution and what people have been told by their medical oncologists."

The study compared results of treatment for 58 patients with one or more brain metastases --who got either sterotactic radiosurgery alone or accompanied by whole brain radiation.

The study was halted after interim results showed that patients who received both therapies had a 49 percent decline in learning and memory function at four months, compared to those who had stereotactic radiosurgery alone. Their mental function decreased by an average of 23 percent.

Survival time for those getting the single treatment was 15.2 months, compared to 5.6 months for those getting the combined therapy, Chang said.

"The expectation was that the two arms would have similar survival," he said. "We were surprised by that result. Previous studies said there was not a difference in survival time."