title: Tangential intensity modulated radiation therapy (IMRT) to the intact breast.
abstract: BACKGROUND
  Inverse-planned intensity modulated radiation therapy (IP-IMRT) has potential benefits over other techniques for tangential intact breast radiotherapy. Possible benefits include increased homogeneity, faster planning time, less inter-planner variability and lower doses to organs at risk (OAR). We therefore conducted a pilot study of previously treated intact breast patients to compare the current forward-planned 'field-in-field' technique (FP-IMRT) with an IP-IMRT alternative.
  
  
  METHODS
  The IP-IMRT plans of 20 patients were generated from a template created for the planning system. All patients were prescribed adjuvant whole breast radiotherapy using a hypofractionated regimen of 40.05 Gy in 15 fractions over 3 weeks. Plans were assessed based on visual inspection of coverage as well as statistical analysis and compared to the clinically acceptable FP-IMRT plans. Patients were planned retrospectively in Monaco 3.2®using a laterality-specific, tangential planning template. Minor adjustments were made as necessary to meet the planning criteria in the protocol. Dose coverage, maximums, homogeneity indices and doses to OAR were recorded.
  
  
  RESULTS
  The IP-IMRT plans provided more consistent coverage (38.18 Gy vs. 36.08 Gy of D95; P = 0.005), a comparable though higher average maximum (D2 = 42.52 Gy vs. 42.08 Gy; P = 0.0001), more homogeneous plans (homogeneity index = 0.908 vs. 0.861; P = 0.01) and somewhat lower V20 heart and lung doses (0.11% vs. 0.89% for heart; 5.4% vs. 7.52% for lung) than FP-IMRT (P > 0.05).
  
  
  CONCLUSIONS
  Clinically acceptable plans have been generated using the IP-IMRT templates in Monaco. Improvements in consistency and quality were seen when compared to the FP-IMRT plans. The template-based process is an efficient method to inversely plan IMRT for breast patients.
authors.affiliation: Department of Radiation Oncology, Mid North Coast Cancer Institute, Port Macquarie Base Hospital, Port Macquarie, New South Wales, Australia.
authors.forename: Jenna
authors.initials: J
authors.lastname: Dean
authors.affiliation: Department of Radiation Oncology, Mid North Coast Cancer Institute, Port Macquarie Base Hospital, Port Macquarie, New South Wales, Australia.
authors.forename: Carmen J
authors.initials: CJ
authors.lastname: Hansen
authors.affiliation: Department of Radiation Oncology, Mid North Coast Cancer Institute, Coffs Harbour Health Campus, Coffs Harbour, New South Wales, Australia.
authors.forename: Justin
authors.initials: J
authors.lastname: Westhuyzen
authors.affiliation: Department of Radiation Oncology, Mid North Coast Cancer Institute, Port Macquarie Base Hospital, Port Macquarie, New South Wales, Australia.
authors.forename: Brett
authors.initials: B
authors.lastname: Waller
authors.affiliation: Department of Radiation Oncology, Mid North Coast Cancer Institute, Coffs Harbour Health Campus, Coffs Harbour, New South Wales, Australia.
authors.forename: Kirsty
authors.initials: K
authors.lastname: Turnbull
authors.affiliation: Department of Radiation Oncology, Mid North Coast Cancer Institute, Coffs Harbour Health Campus, Coffs Harbour, New South Wales, Australia.
authors.forename: Maree
authors.initials: M
authors.lastname: Wood
authors.affiliation: Department of Radiation Oncology, Mid North Coast Cancer Institute, Port Macquarie Base Hospital, Port Macquarie, New South Wales, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Last
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000009:adverse effects / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*
keywords: Breast cancer; intensity modulated radiotherapy; radiotherapy; radiotherapy planning