Single Versus Multifraction Salvage Spine Stereotactic Radiosurgery for Previously Irradiated Spinal Metastases

Inclusion Criteria: 1. All patients must have histologic proof of solid tumor malignancy and radiographic evidence of spine metastasis 2. Age \>/=18 years 3. Eastern Cooperative Oncology Group (ECOG) performance status \</=2 (Karnofsky \>/=60%) 4. Life expectancy of greater than 6 months 5. All patients must be able to lie supine 6. All patients must have no more than 3 contiguous vertebral body levels treated at a single site, and no more than 3 discontiguous vertebral body levels treated 7. All patients must have radiographic evidence of progression at a spinal site previously irradiated greater than 6 months prior to randomization. This includes indirect radiation exposure to spinal site. 8. All patients must have received prior conventional external-beam radiation therapy (cEBRT) to the site of interest to no more than a critical neural tissue dose equivalent dose (EQD)2/2 of 42 Gy in a single session or 50 Gy cumulative over multiple sessions and cauda equina dose EQD2/2 of 50 Gy in a single session or 60 Gy cumulative over multiple session. EQD2/2 is calculated as follows: EQD2/2= biologically effective dose (BED)/(1+d/alpha beta)) where BED=nd(1+d/(alpha beta)) and n=number of fractions, d=dose per fraction and alpha beta ratio of 2. 9. All patients must have a vertebral body site to be treated located from T1 to L5 10. Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. 11. All patients must sign informed consent verifying that they are aware of the investigational nature of this study in keeping with the rules and policies of MD Anderson Cancer Center. The only acceptable consent is the one approved by MD Anderson IRB. 12. Patients undergoing prior surgery or laser interstitial thermotherapy are allowed 13. Both men and women of all races and ethnic groups are eligible for this trial. Exclusion Criteria: 1. Patients unable to undergo magnetic resonance imaging (MRI) of the spine 2. Prior radiation at the site of interest within 6 months 3. Prior history of radiation at the site of interest resulting in a critical neural tissue dose of EQD2/2 of \>42 Gy in a single session 4. Patients unable to lie flat comfortably for 2 hours 5. Pregnancy status will be obtained at time of consent as is routine for all radiation patients. Pregnant women are excluded from this study because radiation has the potential for teratogenic or abortifacient effects 6. Patients with a histology of lymphoma and myeloma histologies