title: Osteoradionecrosis following treatment for head and neck cancer and the effect of radiotherapy dosimetry: the Guy's and St Thomas' Head and Neck Cancer Unit experience.
abstract: OBJECTIVE
  To analyze clinical features, dosimetric parameters, and outcomes of osteoradionecrosis (ORN).
  
  
  METHODS
  Thirty-six patients with ORN who had been previously treated with radiotherapy (RT) were retrospectively identified between January 2009 and April 2014. ORN volumes were contoured on planning computed tomography (CT) scans. Near maximum dose (D2%), minimum dose (Dmin), mean dose (Dmean), and percentage of bone volume receiving 50 Gy (V50) were examined. Clinical and dosimetric variables were considered to compare ORN resolution versus ORN persistence.
  
  
  RESULTS
  Median interval time from end of RT to development of ORN was 6 months. Of the ORN cases, 61% were located in the mandible. Dmean to affected bone was 57.6 Gy, and 44% had a D2% 65 Gy or greater. Smoking was associated with ORN persistence on univariate analysis, but no factors were found to impact ORN resolution or progression on logistic regression.
  
  
  CONCLUSIONS
  Prevention strategies for ORN development should be prioritized. Dose-volume parameters could have a role in preventing ORN.
authors.affiliation: Department of Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK; Department of Radiotherapy, Policlinico Umberto I, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: De Felice
authors.affiliation: Department of Medical Physics, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Thomas
authors.affiliation: Oral Surgery Department, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Vinod
authors.initials: V
authors.lastname: Patel
authors.affiliation: Department of Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Steve
authors.initials: S
authors.lastname: Connor
authors.affiliation: Department of Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Andriana
authors.initials: A
authors.lastname: Michaelidou
authors.affiliation: Oral Surgery Department, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Sproat
authors.affiliation: Oral Surgery Department, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Jerry
authors.initials: J
authors.lastname: Kwok
authors.affiliation: Department of Sedation and Special Care Dentistry, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Mary
authors.initials: M
authors.lastname: Burke
authors.affiliation: Department of Sedation and Special Care Dentistry, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Damien
authors.initials: D
authors.lastname: Reilly
authors.affiliation: Head and Neck Cancer Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: McGurk
authors.affiliation: Head and Neck Cancer Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Ricard
authors.initials: R
authors.lastname: Simo
authors.affiliation: Head and Neck Cancer Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Lyons
authors.affiliation: Head and Neck Cancer Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Oakley
authors.affiliation: Head and Neck Cancer Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Jeannon
authors.affiliation: Department of Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Mary
authors.initials: M
authors.lastname: Lei
authors.affiliation: Department of Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK. Electronic address: teresa.guerrerourbano@gstt.nhs.uk.
authors.forename: Teresa Guerrero
authors.initials: TG
authors.lastname: Urbano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010025:Osteoradionecrosis / Q000000981:diagnostic imaging* / Q000209:etiology*; D010147:Pain Measurement; D011874:Radiometry; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012307:Risk Factors