Adding whole-brain radiation therapy to highly-focused radiation therapy does not improve survival for patients with cancer and brain metastases, but it may reduce the likelihood of the recurrence of brain metastases, according to a study in the June 7 issue of the Journal of the American Medical Association.
Brain metastases (lesions in the brain due to spread of cancers occurring elsewhere) occur in 20 percent to 40 percent of all patients with cancer and are generally associated with a poor prognosis, according to background information in the article. It has been believed that in brain metastases, the entire brain is "seeded" with micrometastatic disease, even when only a single intracranial lesion is detected. Consequently, whole-brain radiation therapy (WBRT), which has possible adverse effects, has been the dominant treatment. Recently, the assumption that the entire brain is seeded with micrometastases has been questioned. For patients who truly have limited intracranial disease, the potential exists that WBRT could be replaced by more focused therapeutic options such as resection (partial surgical removal) or stereotactic radiosurgery (SRS), which delivers high-dose, focal radiation, with less long-term adverse effects than WBRT. These therapies have been used with increasing frequency. It has been unclear whether adding WBRT to SRS improves survival or neurologic function compared with SRS alone.
Hidefumi Aoyama, M.D., Ph.D., of Hokkaido University Graduate School of Medicine, Sapporo, Japan, and colleagues conducted a randomized controlled trial comparing WBRT plus SRS vs. SRS alone for patients with limited (defined as 4 or less) brain metastases. The study included 132 patients enrolled at 11 hospitals in Japan between October 1999 and December 2003. Patients were randomly assigned to receive WBRT plus SRS (65 patients) or SRS alone (67 patients).