Inclusion Criteria:

- Solitary or oligometastatic spine disease (maximum 5 sites of metastases), or bone
only metastatic disease (regardless of the number) in otherwise high performance
status patients, or patients with diffuse metastatic disease where the patient
survival is expected to be at least 6 months

- Maximum of 2 consecutive spinal segments involved by tumor for treatment otherwise a
maximum of 3 sites within the spine to be treated in a single session

- Previously irradiated: up to one course where the maximum BED previously delivered is
no more than 100 Gy2 (50 Gy2/2) and >5 month interval from prior radiation to
planned SBRT (Cohort 2) or first part of cohort 3

- Karnofsky Performance Status >60

- Had an MRI or CT documented spinal tumor and MRI of full spine no more than 8 weeks
prior to SBRT (if patients cannot have a MRI then a CT myelogram is required)

- Had a histological confirmation of neoplastic disease

- Expected to have survival of > 3 months regardless of the number of metastases

- Able to lie still and in a supine position on the treatment couch for up to 1 hour

- Age >18

- Adequate Bowel or urinary function

Exclusion Criteria:

- A Pacemaker such that MRI cannot be performed or the treatment cannot be delivered
safely

- Scleroderma or connective tissue disease as a contra-indication to radiotherapy

- Unable to lie supine (i.e. tolerate treatment)

- Previously treated with any radionuclides within 30 days prior to SBRT

- Had external beam radiotherapy to the same area less than 5 months prior to SBRT
and/or a course of radiation previously delivered >100 Gy2 (50 Gy2/2)

- Significant or progressive neurologic deficit

- Malignant epidural spinal cord compression or cauda equina syndrome

- Spine instability, or neurological deficit resulting from bony compression of neural
structures

- Receiving chemotherapy for at least 1 week prior to SBRT and chemotherapy for one
week following SBRT

- Expected patient survival < 3 months