Treating Brain Tumors With Targeted Radiation
Damage to thinking and memory less than with radiation for entire brain, while survival is similar, study finds
Up to now, doctors have tended to treat cancer patients who have developed brain tumors that spread from other parts of the body by first using targeted radiosurgery to treat the lesions, and then using whole-brain radiation therapy to reduce the likelihood of future tumors cropping up, Brown said.
That strategy has been based on earlier studies that found whole-brain radiation is much better at preventing future brain lesions, and that tumors are more likely to recur in patients who receive radiotherapy alone, he said.
But based on these new findings, doctors likely will begin recommending whole-brain radiation therapy only for patients with aggressive brain cancer or with other cancers that tend to cause many brain tumors, said Dr. Brian Michael Alexander, a radiation oncologist at Dana-Farber Cancer Institute and a professor of radiation oncology at Harvard Medical School in Boston.
"This study will help shape treatment decisions for thousands of current and future patients," he said. "As doctors, we want the very best for our patients, and sometimes giving less treatment offers the best result."
Alexander said he has some cancer patients he has treated "for years" with targeted brain radiosurgery, zapping new lesions as they occur, without ever resorting to whole-brain radiation therapy.
In the study, 213 patients with cancer that had spread to their brains received radiosurgery, and then about half also received follow-up whole-brain radiation therapy. All of the patients had one to three small brain tumors, up to 3 centimeters in width.
Follow-up tests of mental ability found that patients who received whole-brain radiation therapy experienced a 30 percent decline in immediate recall, compared with 8 percent of patients who only received radiosurgery. Immediate recall is the ability to hold onto a small amount of information over a few seconds.
In addition, whole-brain radiation patients experienced a greater decline in short-term memory, an average 51 percent compared with a 20 percent decline in radiosurgery patients.
Verbal ability also took a hit, with whole-brain radiation patients experiencing an average 19 percent decrease compared with just 2 percent of radiosurgery patients.