The aggregate of data pertaining to brain metastases suggests that optimal results are achievable with a 2-pronged approach that addresses both the specific focus (with surgery or radiosurgery) and the surrounding brain parenchymal tissue that may harbor micrometastases. Patterns of failure following treatment of metastases that arise in the posterior fossa have not been reliably defined. Although most would agree that radiosurgery alone is not sufficient treatment for focal metastases in the cerebellum, it may be possible to deliver less than WBI as an "expanded port" beyond the SRS volume.