title: Treatment optimization using computed tomography-delineated targets should be used for supraclavicular irradiation for breast cancer.
abstract: BACKGROUND
  The purpose of this study was to determine whether the use of optimized CT treatment planning offered better coverage of axillary level III (LIII)/supraclavicular (SC) targets than the empirically derived dose prescription that are commonly used.
  
  
  METHODS
  Thirty-two consecutive breast cancer patients who underwent CT treatment planning of a SC field were evaluated. Each patient was categorized according to body mass index (BMI) classes: normal, overweight, or obese. The SC and LIII nodal beds were contoured, and four treatment plans for each patient were generated. Three of the plans used empiric dose prescriptions, and these were compared with a CT-optimized plan. Each plan was evaluated by two criteria: whether 98% of target volume receive >90% of prescribed dose and whether < 5% of the irradiated volume received 105% of prescribed dose.
  
  
  RESULTS
  The mean depth of SC and LIII were 3.2 cm (range, 1.4-6.7 cm) and 3.1 (range, 1.7-5.8 cm). The depth of these targets varied according across BMI classes (p = 0.01). Among the four sets of plans, the CT-optimized plans were the most successful at achieving both of the dosimetry objectives for every BMI class (normal BMI, p = .003; overweight BMI, p < .0001; obese BMI, p < .001).
  
  
  CONCLUSIONS
  Across all BMI classes, routine radiation prescriptions did not optimally cover intended targets for every patient. Optimized CT-based treatment planning generated the most successful plans; therefore, we recommend the use of routine CT simulation and treatment planning of SC fields in breast cancer.
authors: Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
authors: Raweewan
authors: R
authors: Liengsawangwong
authors: Tse-Kuan
authors: TK
authors: Yu
authors: Tzouh-Liang
authors: TL
authors: Sun
authors: Jeremy J
authors: JJ
authors: Erasmus
authors: George H
authors: GH
authors: Perkins
authors: Welela
authors: W
authors: Tereffe
authors: Julia L
authors: JL
authors: Oh
authors: Wendy A
authors: WA
authors: Woodward
authors: Eric A
authors: EA
authors: Strom
authors: Mohammad
authors: M
authors: Salephour
authors: Thomas A
authors: TA
authors: Buchholz
mesh_terms: D001365:Axilla; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000145:classification / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D002968:Clavicle; D005260:Female; D006801:Humans; D015182:Lymphatic Irradiation / Q000379:methods*; D009765:Obesity / Q000145:classification; D050177:Overweight / Q000145:classification; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed