title: Does inverse-planned intensity-modulated radiation therapy have a role in the treatment of patients with left-sided breast cancer?
abstract: BACKGROUND
  The purpose of the study was to determine if multi-field inverse-planned intensity-modulated radiation therapy (IMRT) improves on the sparing of organs at risk (heart, lungs and contralateral breast) when compared with field-in-field forward-planned RT (FiF).
  
  
  METHODS
  The planning CT scans of 10 women with left-sided breast cancer previously treated with whole-breast RT on an inclined breast board with both arms supported above the head were retrieved. The whole breast planning target volume (PTV) was defined by clinical mark-up and contoured on all relevant CT slices as were the organs at risk. For each patient, three plans were generated using FiF, five- and nine-field inverse-planned IMRT, all to a total dose of 50 Gy to the whole breast. Mean and maximum doses to the organs at risk and the homogeneity index (HI) of the whole-breast PTV were compared.
  
  
  RESULTS
  The mean heart dose for the FiF plans was 2.63 Gy compared with 4.04 Gy for the five-field and 4.30 Gy for the nine-field IMRT plans, with no significant differences in the HI of the whole-breast PTV in all plans. The FiF plans resulted in a mean contralateral breast dose of 0.58 Gy compared with 0.70 and 2.08 Gy for the five- and nine-field IMRT plans, respectively.
  
  
  CONCLUSIONS
  FiF resulted in a lower mean heart and contralateral breast dose with comparable HI of the whole-breast PTV in comparison with inverse-planned IMRT using five or nine fields.
authors.affiliation: Departments of Radiation Oncology Physical Sciences Biostatistics and Clinical Trials Radiation Therapy, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
authors.forename: Alison L
authors.initials: AL
authors.lastname: Stillie
authors.forename: Tomas
authors.initials: T
authors.lastname: Kron
authors.forename: Alan
authors.initials: A
authors.lastname: Herschtal
authors.forename: Colin
authors.initials: C
authors.lastname: Hornby
authors.forename: Jim
authors.initials: J
authors.lastname: Cramb
authors.forename: Kelly
authors.initials: K
authors.lastname: Sullivan
authors.forename: Boon
authors.initials: B
authors.lastname: Chua
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D058958:Organs at Risk / Q000528:radiation effects; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated