title: SBRT for early-stage glottic larynx cancer-Initial clinical outcomes from a phase I clinical trial.
abstract: OBJECTIVE
  To confirm safety and feasibility of hypofractionated SBRT for early-stage glottic laryngeal cancer.
  
  
  METHODS
  Twenty consecutive patients with cTis-T2N0M0 carcinoma of glottic larynx were enrolled. Patients entered dose-fractionation cohorts of incrementally shorter bio-equivalent schedules starting with 50 Gy in 15 fractions (fx), followed by 45 Gy/10 fx and, finally, 42.5 Gy/5 fx. Maximum combined CTV-PTV expansion was limited to 5 mm. Patients were treated on a Model G5 Cyberknife (Accuray, Sunnyvale, CA).
  
  
  RESULTS
  Median follow-up is 13.4 months (range: 5.6-24.6 months), with 12 patients followed for at least one year. Maximum acute toxicity consisted of grade 2 hoarseness and dysphagia. Maximum chronic toxicity was seen in one patient treated with 45 Gy/10 fx who continued to smoke >1 pack/day and ultimately required protective tracheostomy. At 1-year follow-up, estimated local disease free survival for the full cohort was 82%. Overall survival is 100% at last follow-up.
  
  
  CONCLUSIONS
  We were able to reduce equipotent total fractions of SBRT from 15 to 5 without exceeding protocol-defined acute/subacute toxicity limits. With limited follow-up, disease control appears comparable to standard treatment. We continue to enroll to the 42.5 Gy/5 fx cohort and follow patients for late toxicity.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01984502.
authors.affiliation: Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: David L
authors.initials: DL
authors.lastname: Schwartz
authors.affiliation: Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Alan
authors.initials: A
authors.lastname: Sosa
authors.affiliation: Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Chun
authors.affiliation: Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Chiuxiong
authors.initials: C
authors.lastname: Ding
authors.affiliation: Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Xian-Jin
authors.initials: XJ
authors.lastname: Xie
authors.affiliation: Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Lucien A
authors.initials: LA
authors.lastname: Nedzi
authors.affiliation: Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Timmerman
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Baran D
authors.initials: BD
authors.lastname: Sumer
mesh_terms: D019583:Dose Fractionation, Radiation; D005260:Female; D005931:Glottis / Q000528:radiation effects*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D008983:Molybdoferredoxin; D009367:Neoplasm Staging; D016634:Radiosurgery; D016896:Treatment Outcome
chemical_list: D008983:Molybdoferredoxin