Limited brain metastases: a narrative review.

Limited brain metastases refer to an oligometastatic state in the brain for which focal therapy with stereotactic radiosurgery (SRS) is appropriate. The definition of what is considered "limited" for brain metastases, however, is not well defined. Multiple recent randomized trials show that metastasis-directed therapy with surgery or stereotactic radiation can prolong survival for patients with 1-5 metastases from various primary tumors, but patients with untreated brain metastases were largely excluded from these trials.