Purpose: The primary objective of this study is to determine if chemotherapy with carboplatin and temozolomide significantly affects the response rates, or size of disease, in patients with brain metastases, originating from cancer in other parts of the body, compared to patients who have already been treated with radiation. Survival, causes of death, recurrence of disease in the central nervous system, toxicity, and quality of life will all be measured as secondary objective in this study.