Advanced gamma knife for brain mets

My mom (age 63) just had the gamma knife procedure done yesterday for brain mets.  I am thankful for this option, but it is still very scary.  She has liver and lung mets too.  She is starting chemo again on Tuesday to treat the liver and lung mets.  I pray the gamma knife killed the cancer in the brain.  Anyone else dealing with a similar situation?  She had BC in 2007, had a mastectomy and chemo.  No radiation.  No lymphnodes showed cancer cells, but I guess some got out.