RAD ONC FREEDOM Oncology Pain

Inclusion Criteria: 1. Male or female ≥ 18 years of age on day of SRS treatment. 2. Documentation of insufficiently controlled mixed, complex cancer pain based on Brief Pain Inventory (BPI) \>8/10 despite optimization of opioid regimen 3. Not eligible for or willing to undergo further pain-relieving interventions 4. Written informed consent (and assent when applicable) obtained from patient or patient's legal representative and ability for patient to comply with the study requirements and agree to undergo the study's SRS treatment plan. Exclusion Criteria: 1. Pregnant, breastfeeding, or unwilling to practice birth control during participation in the study. 2. Claustrophobia or inability to life flat 3. Inability to undergo routine imaging studies 4. Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data. 5. Current history of intracranial malignancy or brain metastasis 6. Any prior intracranial irradiation 7. Previous history of craniotomy, deep brain stimulation (DBS) or laser interstitial themal therapy (LITT). 8. Presence of intracranial hardware such as leads for DBS or any other material that may interfere with safe treatment. 9. Any comorbidity or condition which would limit full compliance with the protocol