title: Phase 1/2 trial of single-session stereotactic body radiotherapy for previously unirradiated spinal metastases.
abstract: BACKGROUND
  In this phase 1/2 study, the authors tested the hypothesis that single-fraction stereotactic body radiotherapy (SBRT) for previously unirradiated spinal metastases is a safe, feasible, and efficacious treatment approach.
  
  
  METHODS
  All patients were evaluated by a multidisciplinary team. Spinal magnetic resonance imaging studies were obtained before treatment and at regular intervals to define both target volume and response to treatment. SBRT was delivered to a peripheral dose of 16 to 24 grays in a single fraction while limiting the dose to the spinal cord. Higher doses were used for renal cell histology. The National Cancer Institute Common Toxicity Criteria 2.0 and McCormick neurologic function score were used as toxicity assessment tools.
  
  
  RESULTS
  In total, 61 patients who had 63 tumors of the noncervical spine were enrolled and received SBRT between 2005 and 2010 on a prospective, phase 1/2 trial at The University of Texas M. D. Anderson Cancer Center. The mean follow-up was 20 months. The actuarial 18-month imaging local control rate for all patients was 88%, the actuarial 18-month overall survival rate for all patients was 64%, and the median survival for all patients was 30 months. No significant differences in outcomes were noted with respect to tumor histology or SBRT dose. Two patients experienced radiation adverse events (grade 3 or higher). The actuarial rate of 18-month freedom from neurologic deterioration from any cause was 82%.
  
  
  CONCLUSIONS
  Data from this phase 1/2 trial supported an expanded indication for SBRT as first-line treatment of spinal metastases in selected patients. The authors concluded that additional studies that can prospectively identify predictive factors for spinal cord toxicity after SBRT are warranted to minimize the incidence of this serious yet rare complication.
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA.
authors.forename: Amit K
authors.initials: AK
authors.lastname: Garg
authors.forename: Almon S
authors.initials: AS
authors.lastname: Shiu
authors.forename: James
authors.initials: J
authors.lastname: Yang
authors.forename: Xin-Shelley
authors.initials: XS
authors.lastname: Wang
authors.forename: Pamela
authors.initials: P
authors.lastname: Allen
authors.forename: Barry W
authors.initials: BW
authors.lastname: Brown
authors.forename: Patricia
authors.initials: P
authors.lastname: Grossman
authors.forename: Erik K
authors.initials: EK
authors.lastname: Frija
authors.forename: Mary Frances
authors.initials: MF
authors.lastname: McAleer
authors.forename: Syed
authors.initials: S
authors.lastname: Azeem
authors.forename: Paul D
authors.initials: PD
authors.lastname: Brown
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Rhines
authors.forename: Eric L
authors.initials: EL
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D013125:Spinal Neoplasms / Q000532:radiotherapy* / Q000556:secondary*