Patients with newly diagnosed brain metastases who undergo sterotactic radiosurgery plus whole-brain radiation therapy experience significant memory loss; therefore, stereotactic radiosurgery alone is the preferred method of treatment for these patients, according to the results of a study published in the Lancet Oncology.
For decades, whole-brain radiation therapy (WBRT) has been the standard treatment for patients with brain metastases. However, stereotactic radiosurgery (SRS) is a more precise treatment that delivers a high dose of radiation to a highly defined target—in other words, the radiation is delivered directly to the cancer while sparing the healthy surrounding tissues. In recent years, SRS combined with WBRT has shown a survival benefit over WBRT alone. Now, however, researchers are evaluating whether SRS alone can provide the same benefit to patients while subjecting them to fewer side effects.
Researchers from the M. D. Anderson Cancer Center conducted a study that included 58 patients who had one to three brain metastases. The patients were assigned to receive SRS alone (30 patients) or SRS plus WBRT (28 patients). The study was stopped early due to a decline in learning and memory function four months post-treatment in patients receiving SRS plus WBRT—52% of patients receiving SRS plus WBRT were likely to have significant learning and memory decline compared with 24% of those receiving SRS alone.
In addition, there were differences in survival between the two groups, though the reasons for this discrepancy are unclear. One theory is that systemic therapy was postponed during radiation, and this could have contributed to a decrease in survival. The median survival for patients in the SRS group was 15.2 months compared with 5. 7 months in the SRS plus WBRT group. Patients in the SRS plus WBRT group were 2-2.5 times more likely to die of neurologic or systemic complications than patients receiving SRS alone.
The researchers concluded that SRS alone (in addition to close monitoring) is the preferred treatment for this group of patients in order to preserve quality of life, learning, and memory.
 Chang EL, Wefel JS, Hess KR, et al. Neurocognition in patients with brain metastases treated with radiosurgery or radiosurgery plus whole-brain irradiation: a randomized controlled trial. Lancet Oncology. 2009; 10: 1037-1044.