Untreated brain metastases are usually fatal within a few weeks. The standard treatment for brain metastases is whole brain irradiation. This results on average in an increase in survival by 2 to 4 times compared to withholding irradiation. The majority of patients experience improvement in the level of functioning as a result of irradiation. None-the-less approximately half of patients die because of progression of the brain metastases and their quality of life is often dominated by the effects of brain metastases.