title: Prone left-sided whole-breast irradiation: significant heart dose reduction using end-inspiratory versus end-expiratory gating.
abstract: OBJECTIVE
  To quantify the influence on heart dose metrics of prone left-sided whole-breast irradiation in an end-inspiratory phase (PrIN) versus an end-expiratory phase (PrEX).
  
  
  METHODS
  Twenty patients underwent CT-simulation in PrIN and PrEX. Dynamic intensity-modulated radiotherapy was planned for whole-breast irradiation with a median prescription dose of 40.05Gy in 15 fractions and maximal sparing of the organs at risk. Dose-volume parameters were analyzed for heart, left anterior descending coronary artery, ipsilateral lung and both breasts.
  
  
  RESULTS
  PrIN consistently reduced (P<0.001) heart and left anterior descending coronary artery dose metrics compared to PrEX. Population averages for maximum and mean heart dose were 6.2Gy and 1.3Gy for PrIN versus 21.4Gy and 2.5Gy for PrEX, respectively. Moreover, a maximum heart dose less than 10Gy was achieved in 80% of patients for PrIN. Target dose distribution, ipsilateral lung and contralateral breast sparing by radiation dose were similar for both procedures.
  
  
  CONCLUSIONS
  Inspiratory gating consistently reduced heart dose metrics pointing to a possible benefit of breathing-adapted radiotherapy for prone left-sided whole-breast irradiation.
authors.affiliation: Department of radiotherapy, Ghent university hospital, 9000 Ghent, Belgium; Department of radiotherapy, Clinique et maternité Sainte-Élisabeth, Namur, Belgium. Electronic address: thomas.mulliez@uzgent.be.
authors.forename: T
authors.initials: T
authors.lastname: Mulliez
authors.affiliation: Department of radiotherapy, Ghent university hospital, 9000 Ghent, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Speleers
authors.affiliation: Department of radiotherapy, Clinique et maternité Sainte-Élisabeth, Namur, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Mahjoubi
authors.affiliation: Department of radiotherapy, Clinique et maternité Sainte-Élisabeth, Namur, Belgium.
authors.forename: V
authors.initials: V
authors.lastname: Remouchamps
authors.affiliation: Department of radiotherapy, Clinique et maternité Sainte-Élisabeth, Namur, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Gilsoul
authors.affiliation: Department of radiotherapy, Ghent university hospital, 9000 Ghent, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Veldeman
authors.affiliation: Department of gynaecology, Ghent university hospital, Ghent, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Van den Broecke
authors.affiliation: Department of radiotherapy, Ghent university hospital, 9000 Ghent, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: De Neve
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D019583:Dose Fractionation, Radiation; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000528:radiation effects*; D006801:Humans; D001239:Inhalation; D008168:Lung / Q000000981:diagnostic imaging; D008875:Middle Aged; D058958:Organs at Risk / Q000000981:diagnostic imaging / Q000528:radiation effects; D056888:Patient Positioning / Q000379:methods*; D016684:Prone Position; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated; D014057:Tomography, X-Ray Computed
keywords: Breast; Cancer du sein; Cœur; Gating respiratoire; Heart; Procubitus; Prone position; Radiotherapy; Radiothérapie; Respiratory gating