Spine SABR - Dose-escalated Stereotactic Ablative Body Radiotherapy (SABR) for Solid Tumour Spine Metastases

Inclusion Criteria:

1. Written informed consent obtained prior to any study-related procedures

2. ≥ 18 years of age

3. Life expectancy > 6 months

4. ECOG (Eastern Cooperative Oncology Group) performance status (PS) 0-2

5. Histological diagnosis of malignant primary disease (excluding haematologic,seminomatous or small cell subtype)

6. Diagnosis of oligometastatic disease (OMD) or oligoprogressive disease (OPD) definedas:

7. OMD where there are 1 to 5 metastatic lesions, with a controlled primary tumorbeing optional, but where all metastatic sites must be safely treatable (can besynchronous or metachronous to primary tumor diagnosis) with curative intent OR

8. OPD with 1 to 5 lesions progressing on a background of widespread but stablemetastatic disease OR

9. Systemic therapy-induced OMD where there are 1 to 5 persistent lesions aftersystemic therapy, all safely treatable with SABR

10. Single spinal level from C1 to L5 to be treated for the purpose of the study (co-existing lesion(s) on non-consecutive spinal level(s) may receive RT atInvestigator discretion, if deemed unlikely to interfere with study treatment andassessment of outcomes).

11. Stable spine assessed by Spinal Instability Neoplastic Score (SINS) (SINS 0-6, orSINS 7-12 and not for surgical intervention).

12. Bilsky Grade 0-1a (i.e. minimal (epidural impingement, without deformation of thecalsac) or no epidural disease) as confirmed by Radiation Oncologist

13. Able to lie flat in the treatment position for radiotherapy for up to 60 minutes

14. Females of childbearing potential must not be pregnant or lactating, and must beprepared to take adequate contraception methods during treatment. Males whose femalepartners are of childbearing potential must be prepared to take adequatecontraception methods during treatment. Examples of effective contraception methodsare a condom or a diaphragm with spermicidal jelly, or oral, injectable or implantedbirth control

Exclusion Criteria:

1. Previous radiotherapy or surgery to the proposed SABR treatment site which is likelyto interfere with treatment or assessment of outcomes (for radiotherapy, thisincludes prior thoracic radiotherapy to the lung or oesophagus which would result inoverlap of fields if a T spine lesion will be treated)

2. Patients with symptomatic spinal cord compression or cauda equina syndrome,resulting in bony compression or epidural compression of the spinal cord or caudaequine, respectively

3. Patients with syndromes or conditions associated with increased radiosensitivity

4. Patients with radiosensitive histologies, e.g. myeloma or lymphoma

5. Contraindication to MRI, e.g. MRI-incompatible personal pacemaker in situ

6. Patients with pre-existing osteoporotic fractures of the spine

7. Prior treatment with any radionuclide within 30 days prior to registration

8. Patients who have received chemotherapy within 1 week prior to administration ofprotocol RT or who are expected/planned to receive chemotherapy during RT or within 1 week after completing protocol RT

9. Uncontrolled intercurrent illness that is likely to interfere with treatment orassessment of outcomes, or psychiatric illness/social situations that would limitcompliance with study requirements

10. Evidence of any other significant clinical disorder or laboratory finding that makesit undesirable for the patient to participate in the study, or if it is felt by theresearch / medical team that the patient may not be able to comply with the protocoland follow-up schedule due to psychological, familial, sociological or geographicalconditions

11. Significant or progressive neurological deficit such that emergency surgery orradiation required