title: Reevaluation of postoperative radiation dose in the management of human papillomavirus-positive oropharyngeal cancer.
abstract: The purpose of this study was to compare outcomes of patients with p16-positive oropharyngeal squamous cell carcinoma (SCC) treated with postoperative intensity-modulated radiotherapy (IMRT) before and after an institutional dose reduction policy effective on February 2009.
  
  
  
  Between 1998 and 2013, 175 consecutive patients with p16-positive oropharyngeal SCC with extracapsular extension (ECE) and/or close or positive margins were treated postoperatively to 66 Gy (n = 109) or 60 Gy (n = 66) in 2 Gy/fx.
  
  
  
  Between the 66 and 60 Gy groups, there was no difference in tumor classification (pT4 vs pT1-T3; p = .181) and nodal classification (pN2c-N3 vs pN0-N2b; p = .704), and American Joint Committee on Cancer (AJCC) group stage (IV vs I-III; p = .473). Median follow-up was 5.9 years overall (66 Gy: 7.4 years; 60 Gy: 4.0 years). There was no difference in locoregional recurrence-free survival (2-year: 98.1% vs 98.5%; p = .421).
  
  
  
  This study suggests that treating p16-positive oropharyngeal SCC with ECE and/or close or positive margins with postoperative IMRT to 60 Gy may not compromise locoregional recurrence-free survival compared to 66 Gy. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.
authors.affiliation: Saint Louis University School of Medicine, St. Louis, Missouri.
authors.forename: Re-I
authors.identifier: 0000-0003-2642-5712
authors.initials: RI
authors.lastname: Chin
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Spencer
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Todd
authors.initials: T
authors.lastname: DeWees
authors.affiliation: Rutgers New Jersey Medical School, Newark, New Jersey.
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Hwang
authors.affiliation: Saint Louis University School of Medicine, St. Louis, Missouri.
authors.forename: Pranav
authors.initials: P
authors.lastname: Patel
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Parul
authors.initials: P
authors.lastname: Sinha
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Hiram A
authors.initials: HA
authors.lastname: Gay
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri.|Department of Surgery, University of Auckland School of Medicine, Auckland, New Zealand.
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Haughey
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Brian
authors.initials: B
authors.lastname: Nussenbaum
authors.affiliation: Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Adkins
authors.affiliation: Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri.|Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: James S
authors.initials: JS
authors.lastname: Lewis
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri. wthorstad@radonc.wustl.edu.
authors.forename: Wade L
authors.initials: WL
authors.lastname: Thorstad
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy* / Q000601:surgery / Q000821:virology; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D052162:Human papillomavirus 16 / Q000302:isolation & purification; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D000072662:Margins of Excision; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009959:Oropharyngeal Neoplasms / Q000532:radiotherapy* / Q000601:surgery / Q000821:virology; D011184:Postoperative Period; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated
keywords: adjuvant radiotherapy; human papillomavirus (HPV); oropharynx; p16; survival