The investigators propose to conduct a study in medically refractory cancer pain patients utilizing radiosurgery to ablate the pituitary hypophysis, as well as neuromodulate the centromedian and parafascicular complexes within the thalami - the so-called triple target. This involves treating the pituitary hypophysis and thalamus to a dose of 90 Gy. These patients will have previously failed to achieve adequate pain control with opioid pain regimens and interventional approaches. The trial will involve a multidisciplinary approach involving radiation oncology, neurosurgery, palliative care, and medical oncology colleagues across UCLA.

Refractory pain is one of the most debilitating challenges in oncology patients, particularly at the end of life. Over 60% of cancer patients experience pain, with 30% of these patients becoming refractory to opioid pain medication. Interventional techniques such as nerve blocks and pain pumps only transiently relieve pain and are often not viable for advanced cancer patients. In patients with diffuse metastatic disease with less than 3-6 months survival, there is a pressing need for a rapid and thorough relief of pain sensation.

Recently, using highly focused radiation delivered to very unique targets in the brain, patients can have marked reduction in perceived pain. There are centers in the brain dubbed as gateways of pain, including the pituitary hypophysis1 and the centromedian and parafascicular complexes2, with some preliminary data also involving the anterior cingulum. Ablation or neuromodulation of these targets with focused high doses of radiation have been shown in small series to provide pain relief in ~3.5 days with a 50% reduction of perceived pain.

The investigators propose to conduct a study in medically refractory cancer pain patients utilizing radiosurgery to ablate the pituitary hypophysis, as well as neuromodulate the centromedian and parafascicular complexes within the thalami - the so-called “triple target.†3 This involves treating the pituitary hypophysis and thalamus to a dose of 90 Gy. These patients will have previously failed to achieve adequate pain control with opioid pain regimens and interventional approaches. This trial will involve a multidisciplinary approach involving radiation oncology, neurosurgery, palliative care, and medical oncology colleagues across UCLA.

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