Ipilimumab Induction in Patients With Melanoma Brain Metastases Receiving Stereotactic Radiosurgery

This is a randomized Phase II selection study investigating the use of ipilimumab induction prior to stereotactic radiosurgery (SRS), versus no induction, for melanoma brain metastases. Participants will be randomized to Arm A "Induction" (two doses of ipilimumab prior to SRS, two doses of ipilimumab after SRS) versus Arm B "No induction" (SRS first, followed by 4 doses of ipilimumab). Participants will undergo multiple dynamic contrast-enhanced MRIs of the brain and submit blood samples for immune testing.