title: Comparison of the incidence of osteoradionecrosis with conventional radiotherapy and intensity-modulated radiotherapy.
abstract: Modern techniques of radiotherapy are supposed to decrease the incidence of osteoradionecrosis of the mandible (ORNM). The purpose of this study was to compare the incidence of ORNM after intensity-modulated radiotherapy (IMRT) in comparison to conventional 3D conformal radiotherapy techniques (conventional RT).
  
  
  
  We conducted a retrospective study of consecutive unselected patients treated in a single institution between 2002 and 2012. To minimize confounding effects, only patients with oropharyngeal carcinoma without surgery of the primary site were included.
  
  
  
  The cohorts included 145 patients in the conventional RT group and 89 patients in the IMRT group. Total incidence rate of ORNM was similar for both groups with rates of 11% versus 10% (n = 16 for conventional RT and n = 9 for IMRT; p = 1.0). Subanalysis revealed more ORNM in T4 classified lesions with IMRT (p = .007). Analysis of different risk factors showed no statistically significant difference between ORNM and no-ORNM patients.
  
  
  
  We found no reduction in ORNM with IMRT. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.
authors.affiliation: Department of Oto-Rhino-Laryngology - Head and Neck Surgery, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Thibault De
authors.initials: T
authors.lastname: Maesschalck
authors.affiliation: Department of Oto-Rhino-Laryngology - Head and Neck Surgery, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Dulguerov
authors.affiliation: Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Francesca
authors.initials: F
authors.lastname: Caparrotti
authors.affiliation: Department of Maxillo-Facial Surgery, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Paolo
authors.initials: P
authors.lastname: Scolozzi
authors.affiliation: Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Cristina
authors.initials: C
authors.lastname: Picardi
authors.affiliation: Department of Medical Oncology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Mach
authors.affiliation: Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Koutsouvelis
authors.affiliation: Department of Oto-Rhino-Laryngology - Head and Neck Surgery, Geneva University Hospital, Geneva, Switzerland. pavel.dulguerov@hcuge.ch.
authors.forename: Pavel
authors.initials: P
authors.lastname: Dulguerov
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008334:Mandible / Q000473:pathology / Q000528:radiation effects*; D008336:Mandibular Diseases / Q000453:epidemiology / Q000209:etiology*; D008875:Middle Aged; D009909:Oral Health; D009959:Oropharyngeal Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D010025:Osteoradionecrosis / Q000453:epidemiology / Q000209:etiology*; D011878:Radiotherapy / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis
keywords: cancer; head and neck; intensity-modulated radiotherapy (IMRT); oropharynx; osteoradionecrosis; radiotherapy