Analyzing Preoperative Stereotactic Radiosurgery With Gamma Knife Icon for Brain Metastases

Inclusion Criteria:

1. Voluntary written consent must be given before performance of any study related procedure that's is not part of standard medical care, with the understanding that consent may be withdrawn by the subject at any time without prejudice to future medical care.
2. Female or Male subject's ≥ 18 years old at the time of informed consent.
3. Radiographically confirmed solid tumor brain metastases.
4. Criteria for surgical resection of at least one metastasis per neurosurgeon discretion.
5. Stereotactic radiosurgery candidate per radiation oncologist discretion.
6. A diagnostic MRI Brain or CT Head demonstrating the presence of 1-4 solid tumor brain metastases and lesion to be resected no more than 5 cm in any direction, performed within 30 days prior to stereotactic radiosurgery.
7. For known and unknown primary, diagnosis-specific graded prognostic assessment (ds-GPA) estimated median survival no less than 6 months.
8. Surgical resection able to be performed within 1-10 days after radiosurgery.
9. Patients currently on cytotoxic chemotherapy or immunotherapy are eligible, not including anti-vascular endothelial growth factor (anti-VEGF) therapy.
10. Female subjects who:

    1. Are postmenopausal for at least 1 year before the screening visit, OR
    2. Are surgically sterile, OR

    i. Agree to practice 1 highly effective method and 1 additional effective (barrier) method of contraception, at the same time, from the time of signing the informed consent through 4 months after the last study Intervention (female and male condoms should not be used together), OR ii. Agree to practice true abstinence, when this is in line with the preferred and usual lifestyle of the subject. (Periodic abstinence \[eg, calendar, ovulation, symptothermal, post-ovulation methods\] withdrawal, spermicides only, and lactational amenorrhea are not acceptable methods of contraception.)
11. Male subjects, even if surgically sterilized (ie, status post-vasectomy), who:

    1. Agree to practice effective barrier contraception during the entire study treatment period from the time of signing the informed consent through and through 4 months after the last study Intervention (female and male condoms should not be used together), OR
    2. Agree to practice true abstinence, when this is in line with the preferred and usual lifestyle of the subject. (Periodic abstinence \[eg, calendar, ovulation, symptothermal, post-ovulation methods for the female partner\] withdrawal, spermicides only, and lactational amenorrhea are not acceptable methods of contraception.)

Exclusion Criteria:

1. Patients who received anti-VEGF therapy within 6 weeks prior to enrollment, as there is increased risk of fatal brain hemorrhage with surgical resection.
2. Major medical illnesses or psychiatric impairments, which in the investigator's opinion will prevent administration or completion of the protocol therapy and/or interfere with surveillance.
3. Patients with more than 4 brain metastases on MRI Brain.
4. Lesion to be resected is more than 5 cm in any dimension.
5. Patients with leptomeningeal metastases documented by MRI or cerebrospinal fluid (CSF) evaluation.
6. Previous whole brain radiation therapy.
7. Previous radiation therapy to the lesion to be resected.
8. Planned adjuvant focal therapy including additional radiation therapy to the brain.
9. Not a surgical candidate per neurosurgeon discretion.
10. Not a stereotactic radiosurgery candidate per radiation oncologist discretion.
11. Surgery unable to be performed between 1 - 10 days after radiosurgery.
12. Women who are pregnant or nursing as treatment involves unforeseeable risks to the fetus or child.
13. Patients who have a known or unknown primary and have an estimated median survival of less than 6 months per ds-GPA.