Single Versus Multiple Fractionated SSRS for Spinal Metastases

Inclusion criteria

To be eligible for inclusion, patients must fulfill the following criteria:

1. Patients with a histologic diagnosis of non-hematopoietic malignancy
2. Radiographic evidence of localized spine metastases without leptomeningeal involvement or intramedullary lesion
3. Maximum three separate sites with a maximal involvement of two continuous vertebral levels
4. Patients do not have prior radiotherapy to the index spine(s)
5. Patients with metastatic epidural spinal cord compression (≥ grade 2) at the index spine(s) who will not be treated with spine surgery after evaluation by neurosurgeon or orthopedic doctor
6. Age ≥ 20 years
7. Karnofsky performance status (KPS) ≥ 60%.
8. Life expectancy of ≥ 4 month.
9. Women of childbearing potential and male participants must practice adequate contraception
10. Patients must be able to comply with the study protocol and follow-up schedules and provide study-specific informed consent

Exclusion criteria Patients fulfill any of the following criteria will be excluded from this trial

1. Prior radiotherapy to the index spine(s)
2. Serum creatinine \> 2.0 mg/dL within 90 days prior registration
3. Contraindication to MRI such as implanted metal devices or foreign bodies, severe claustrophobia
4. Patients with leptomeningeal involvement or intramedullary metastasis
5. Inability to tolerate treatment procedure
6. Bony retropulsion causing neurologic abnormality
7. Severe, active comorbidities which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and adverse events of the protocol, or limit compliance with study requirements, defined as follows:

   * Uncontrolled active infection requiring intravenous antibiotics at the time of registration
   * Transmural myocardial infarction ≤ 6 months prior to registration
   * Unstable angina or congestive heart failure requiring hospitalization ≤ 6 months prior to registration
   * Life-threatening uncontrolled clinically significant cardiac arrhythmias
   * Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects
   * Chronic obstructive pulmonary disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy at the time of registration
   * Uncontrolled psychiatric disorder
8. Will receive any other investigational agent or chemotherapy and/or target therapies during treatment
9. Women of childbearing potential and male participants who are sexually active and not willing/able to use medically acceptable forms of contraception; this exclusion is necessary because the radiation treatment involved in this study may be significantly teratogenic