title: A dosimetric study of cardiac dose sparing using the reverse semi-decubitus technique for left breast and internal mammary chain irradiation.
abstract: OBJECTIVE
  Breath-hold techniques can reduce cardiac dose in breast radiotherapy. The reverse semi-decubitus (RSD) technique is an alternative free-breathing method used at our centre. This study compares the dosimetry of free-breathing supine, RSD and moderate deep inspiration breath-hold (mDIBH) techniques.
  
  
  METHODS
  Twelve patients with left-sided breast cancer who were simulated using standard supine, RSD and mDIBH techniques were identified retrospectively. New plans using standard breast tangents and techniques for internal mammary chain (IMC) nodal coverage were assessed.
  
  
  RESULTS
  Using standard tangents, mean heart dose, heart V25Gy and mean left anterior descending artery (LAD) dose were found to be significantly lower for RSD and mDIBH when compared to free-breathing supine (p ⩽ 0.03). Using wide-tangents, the maximum LAD point dose was also lower for RSD and mDIBH (p ⩽ 0.02). There were no statistically significant dosimetric differences found between the RSD and mDIBH simulation techniques for standard breast-tangent plans, though organ-at-risk doses were lower for mDIBH in wide-tangent plans. There was no improvement in cardiac dosimetry between RSD and free-breathing supine when using an electron field IMC plan.
  
  
  CONCLUSIONS
  For patients unable to tolerate breath-hold, the RSD technique is an alternative approach that can reduce cardiac dose.
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Niglas
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Claire
authors.initials: C
authors.lastname: McCann
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Keller
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Nadiya
authors.initials: N
authors.lastname: Makhani
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Joseph
authors.initials: J
authors.lastname: Presutti
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Danny
authors.initials: D
authors.lastname: Vesprini
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Eileen
authors.initials: E
authors.lastname: Rakovitch
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Alyaa
authors.initials: A
authors.lastname: Elzibak
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
authors.forename: Shahram
authors.initials: S
authors.lastname: Mashouf
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Canada. Electronic address: Justin.Lee@sunnybrook.ca.
authors.forename: Justin
authors.initials: J
authors.lastname: Lee
mesh_terms: D001940:Breast / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000532:radiotherapy*; D062485:Breath Holding; D005260:Female; D006321:Heart / Q000528:radiation effects*; D006801:Humans; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D012119:Respiration; D012189:Retrospective Studies; D016683:Supine Position
keywords: Breast; Cardiac dose; Free-breathing; Radiotherapy