title: Stereotactic Body Radiation Therapy for Spinal Metastases in the Postoperative Setting: A Secondary Analysis of Mature Phase 1-2 Trials.
abstract: To evaluate the outcomes in patients treated on prospective phase 1-2 protocols with postoperative stereotactic body radiation therapy (SBRT) and identify the associated prognostic variables.
  
  
  
  Sixty-six patients with 69 tumors were treated with SBRT on prospective phase 1-2 studies for spinal metastases between 2002 and 2010. All patients underwent SBRT after spine surgery, which included laminectomy, vertebrectomy, or a combination of these techniques. Renal cell carcinoma was the most common histology represented (n=35, 53%) followed by sarcomas (n=13, 20%). Thirty-one patients (47%) were treated with prior conventional radiation to the spine (median dose 30 Gy). Patients were followed up with spinal magnetic resonance imaging (MRI) studies to determine the treated tumor control (TC). Pain and other symptom data were collected prospectively to determine treatment response and toxicity.
  
  
  
  The median follow-up time was 30 months (range, 1-145 months) for all patients and 75 months for living patients (range, 6-145 months). The actuarial 1-year rate of TC was 85%, adjacent vertebral body control was 85%, and overall survival (OS) was 74% (median 29 months). On multivariate competing-risks analysis, sarcoma histology (subhazard ratio [SHR] = 2.38, 95% confidence interval [CI] 1.05-5.6, P=.04) and larger preoperative tumor volumes (SHR=1.01, 95% CI 1.0-1.01, P=.006) were significantly associated with worse TC. Karnofsky performance status was the only significant predictor for OS on multivariate analysis. There were no differences in TC between patients treated with different surgical techniques or different preoperative or postoperative Bilsky grades. There were no grade 3 or higher neurologic toxicities.
  
  
  
  This study represents a large series of prospective data available on patients treated with SBRT in the postoperative setting. The combination of surgery with SBRT can offer patients with metastatic disease to the spine the chance of durable tumor control with minimal toxicity.
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Randa
authors.initials: R
authors.lastname: Tao
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Bishop
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Brownlee
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Pamela K
authors.initials: PK
authors.lastname: Allen
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Settle
authors.affiliation: Department of Radiation Oncology, USC Norris Cancer Hospital, Keck School of Medicine of USC, Los Angeles, California.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Chang
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Neuroradiology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Behrang
authors.initials: B
authors.lastname: Amini
authors.affiliation: Department of Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Nizar M
authors.initials: NM
authors.lastname: Tannir
authors.affiliation: Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Claudio
authors.initials: C
authors.lastname: Tatsui
authors.affiliation: Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Rhines
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Brown
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. Electronic address: ajghia@mdanderson.org.
authors.forename: Amol J
authors.initials: AJ
authors.lastname: Ghia
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015984:Causality; D017321:Clinical Trials, Phase I as Topic / Q000706:statistics & numerical data; D017322:Clinical Trials, Phase II as Topic / Q000706:statistics & numerical data; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000401:mortality*; D011182:Postoperative Care; D011379:Prognosis; D011832:Radiation Injuries / Q000401:mortality*; D016634:Radiosurgery / Q000401:mortality*; D018714:Radiotherapy, Adjuvant; D012307:Risk Factors; D013119:Spinal Cord Injuries / Q000401:mortality*; D013125:Spinal Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000556:secondary*; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology