Background: Breast cancer is one of the most common malignancies that metastasize to the brain. Radiation therapy plays a central role in the management of brain metastases.
Methods: The medical records of 36 patients with brain metastases from breast cancer who underwent whole-brain radiation therapy (WBRT) at Kyoto University Hospital between 1993 and 2001 were reviewed. The treatment outcomes were analyzed retrospectively.
Results: The median age at the time of diagnosis of brain metastases was 52 years. Only 4 patients (11%) had a single metastasis, while the others had multiple metastases. Uncontrolled extracranial metastases were present in 26 patients at the time of diagnosis of brain metastases. All patients received WBRT at a median dose of 31 Gy. Eight patients received conventional external-beam boost irradiation, and 2 received boost stereotactic radiosurgery (SRS). The overall median survival time was 7.9 months. Uncontrolled extracranial metastases except for bone metastases and old age were significantly associated with a poor survival rate. Twenty-six patients (82%) showed initial response, but 15 developed CNS failure, including 9 patients whose tumor recurred at the original site, 4 patients who developed tumors elsewhere in the brain and 3 patients who exhibited meningeal spread. The median duration of intracranial failure was 5.0 months. Whole-brain dose, and total tumor dose did not affect intracranial control.
Conclusions: Radiation therapy yielded a high initial response, but the duration of effect was limited with external beam irradiation alone. New treatment strategies such as adding SRS need to be studied further.