title: Radiotherapy for the prophylaxis of heterotopic ossification: a systematic review and meta-analysis of published data.
abstract: BACKGROUND
  Following surgery, the formation of heterotopic ossification (HTO) can limit mobility and impair quality of life. Radiotherapy has been proven to provide efficacious prophylaxis against HTO, especially in high-risk settings.
  
  
  OBJECTIVE
  The current review aims to determine the factors influencing HTO formation in patients receiving prophylactic radiotherapy.
  
  
  METHODS
  A systematic search of the literature was conducted on Ovid Medline, Embase and the Cochrane Central Register of Controlled Trials. Studies were included if they reported the percentage of sites developing heterotopic ossification after receiving a specified dose of prophylactic radiotherapy. Weighted linear regression analysis was conducted for continuous or categorical predictors.
  
  
  RESULTS
  Extracted from 61 articles, a total of 5464 treatment sites were included, spanning 85 separate study arms. Most sites were from the hip (97.7%), from United States patients (55.2%), and had radiation prescribed postoperatively (61.6%) at a dose of 700cGy (61.0%). After adjusting for radiation site, there was no statistically significant relationship between the percentage of sites developing HTO and radiation dose (p=0.1) or whether radiation was administered preoperatively or postoperatively (p=0.1). Sites with previous HTO formation were more likely to develop recurrent HTO than those without previous HTO formation (p=0.04). There was a statistically significant negative relationship between the HTO development and the cohort mean year of treatment (p=0.007).
  
  
  CONCLUSIONS
  Decreases in rates of HTO over time in this patient population may be a function of more efficacious surgical regimens and prophylactic radiotherapy.
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Marko
authors.initials: M
authors.lastname: Popovic
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Arnav
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Liying
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Yip
authors.affiliation: Division of Orthopaedics, Sunnybrook Health Science Centre, Toronto, Canada.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Kreder
authors.affiliation: Division of Orthopaedics, Sunnybrook Health Science Centre, Toronto, Canada.
authors.forename: Markku T
authors.initials: MT
authors.lastname: Nousiainen
authors.affiliation: Division of Orthopaedics, Sunnybrook Health Science Centre, Toronto, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Jenkinson
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: May
authors.initials: M
authors.lastname: Tsao
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Henry
authors.initials: H
authors.lastname: Lam
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Milica
authors.initials: M
authors.lastname: Milakovic
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Erin
authors.initials: E
authors.lastname: Wong
authors.affiliation: Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada. Electronic address: Edward.Chow@sunnybrook.ca.
authors.forename: Edward
authors.initials: E
authors.lastname: Chow
mesh_terms: D004812:Epidemiologic Methods; D006801:Humans; D009999:Ossification, Heterotopic / Q000517:prevention & control / Q000532:radiotherapy*; D011182:Postoperative Care / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D011788:Quality of Life; D011879:Radiotherapy Dosage; D055502:Secondary Prevention / Q000379:methods
keywords: Dose fractionation; Heterotopic ossification; Orthopedic surgery; Radiotherapy