This study is evaluating the addition of stereotactic radiosurgery (SRS) before or after surgery in treating patients with cancer that has spread to the brain (brain metastases). Stereotactic radiosurgery is a type of radiation therapy that delivers a high dose of radiation only to the small areas of cancer in the brain and avoids the surrounding normal brain tissue. 

The purpose of this study is to compare the usual treatment of having SRS after surgery to receiving SRS before surgery. Receiving SRS before surgery could increase the time without the cancer returning or worsening. Surgery and radiation may stop the tumor from growing for a few months or longer and can reduce symptoms of brain metastases.
   
Participants will be randomized to one of two groups. Randomization is like flipping a coin and there is a 50/50 chance of being assigned to either group.
   
Participants in both groups will get SRS. Participants in one group will receive the radiation treatment after surgery to remove one of the sites of cancer. Participants assigned to the second group will receive the radiation treatments before surgery. 
   
Participants receiving SRS before surgery will be given it as a single treatment over one day (or in some cases a few days) as an outpatient procedure, and will go back to the hospital another day for surgery. Participants having surgery first will go back another day for the SRS.

After surgery, the study team will continue to follow each participant and watch for side effects every 3 months for 2 years, then every 6 months for 2 years. Total study participation will last approximately 4 years after your surgery.