title: Breathing adapted radiation therapy in comparison with prone position to reduce the doses to the heart, left anterior descending coronary artery, and contralateral breast in whole breast radiation therapy.
abstract: OBJECTIVE
  To compare 3 different treatment positions in whole breast radiation therapy in terms of target volume coverage and doses to the organs at risk (OAR).
  
  
  METHODS
  Thirty-four breast cancer (BC) patients (17 right-sided and 17 left-sided) were included in this dosimetric planning study. They all underwent a computed tomography (CT) scan in standard supine position in free-breathing (FB), supine position with gating in deep inspiratory breath hold (DIBH)(G), and prone position (P). Three-dimensional treatment plans were made for all 3 CTs. Target coverage and OAR sparing were evaluated.
  
  
  RESULTS
  Breast volumes varied between 209 and 2814 cm(3). The target coverage, expressed as the mean volume of the breast receiving at least 95% of the prescription dose, was similar for the 3 treatment positions. The mean lung dose and the volume of the lungs receiving >20 Gy were significantly lower in P (1.7 Gy; 2.3%) compared with G (3.4 Gy; 5.6%; P < .0001) and FB (4 Gy; 7.3%; P < .0001). The volume of the contralateral breast receiving >5 Gy was significantly lower in G (P = .001) or FB (P = .004) versus prone. The supine position with gating in DIBH significantly reduced the volume of the heart receiving >30 Gy (V30(heart)), the mean heart (D(heart)), and mean left anterior descending coronary artery (LAD) dose (D(LAD)) for left-sided BC patients (V30(heart) 0.9%, D(heart) 1.6 Gy, DLAD 22.4 Gy) with respect to FB (V30(heart) 4.3%, D(heart) 3.5 Gy, DLAD 30.9 Gy)(V30(heart) and mean D(heart): P ≤ .0001; mean D(LAD): P = .008) and P (V30(heart) 7.9%, D(heart) 5.4 Gy, D(LAD) 36.4 Gy)(V30(heart) and mean D(heart): P = .0004; mean D(LAD): P = .01).
  
  
  CONCLUSIONS
  The coverage of the planning target volume breast was equal for the 3 treatment positions. The lowest doses to the lungs were achieved in prone. The heart, LAD, and contralateral breast were best spared in the supine position with gating in DIBH.
authors.affiliation: Department of Radiation-Oncology, University Hospitals of Leuven, Leuven, Belgium. Electronic address: karolien.verhoeven@uzleuven.be.
authors.forename: Karolien
authors.initials: K
authors.lastname: Verhoeven
authors.affiliation: Department of Radiotherapy, Heilig Hart Hospital of Roeselare, Roeselare, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Sweldens
authors.affiliation: Department of Radiation-Oncology, University Hospitals of Leuven, Leuven, Belgium.
authors.forename: Saskia
authors.initials: S
authors.lastname: Petillion
authors.affiliation: L-Biostat, Catholic University of Leuven, Leuven, Belgium.
authors.forename: Annouschka
authors.initials: A
authors.lastname: Laenen
authors.affiliation: Department of Radiation-Oncology, University Hospitals of Leuven, Leuven, Belgium.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Peeters
authors.affiliation: Department of Radiation-Oncology, University Hospitals of Leuven, Leuven, Belgium.
authors.forename: Hilde
authors.initials: H
authors.lastname: Janssen
authors.affiliation: Department of Radiation-Oncology, University Hospitals of Leuven, Leuven, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Van Limbergen
authors.affiliation: Department of Radiation-Oncology, University Hospitals of Leuven, Leuven, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Weltens
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D062485:Breath Holding; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008327:Mammography; D008875:Middle Aged; D016684:Prone Position; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed