title: Elective breast radiotherapy including level I and II lymph nodes: A planning study with the humeral head as planning risk volume.
abstract: BACKGROUND
  The aim of this study was to assess the dose to the humeral head planning risk volume with the currently used high tangential fields (HTF) and compare different planning techniques for breast radiotherapy including axillary level I and II lymph nodes (PTVn) while sparing the humeral head.
  
  
  METHODS
  Ten patients with left-sided breast cancer were enrolled in a planning study with 16 fractions of 2.66 Gy. Four planning techniques were compared: HTF, HTF with sparing of the humeral head, 6-field IMRT with sparing of the humeral head and VMAT with sparing of the humeral head. The humeral head + 10 mm was spared by restricting V40Gy < 1 cc.
  
  
  RESULTS
  The dose to the humeral head was too high with HTF (V40Gy on average 20.7 cc). When sparing the humeral head in HTF, PTVn V90% decreased significantly from 97.9% to 89.4%. 6-field IMRT and VMAT had a PTVn V90% of 98.2% and 99.5% respectively. However, dose to the lungs, heart and especially the contralateral breast increased with VMAT.
  
  
  CONCLUSIONS
  The humeral head is rarely spared when using HTF. When sparing the humeral head, the 6-field IMRT technique leads to adequate PTV coverage while not increasing the dose to the OARs.
authors.affiliation: Department of Radiation Oncology, Catharina Hospital, Michelangelolaan 2, 5623EJ, Eindhoven, The Netherlands. kathrin.surmann@catharinaziekenhuis.nl.
authors.forename: Kathrin
authors.identifier: http://orcid.org/0000-0003-2485-1793
authors.initials: K
authors.lastname: Surmann
authors.affiliation: Department of Radiation Oncology, Catharina Hospital, Michelangelolaan 2, 5623EJ, Eindhoven, The Netherlands.
authors.forename: Jorien
authors.initials: J
authors.lastname: van der Leer
authors.affiliation: Department of Radiation Oncology, Catharina Hospital, Michelangelolaan 2, 5623EJ, Eindhoven, The Netherlands.
authors.forename: Tammy
authors.initials: T
authors.lastname: Branje
authors.affiliation: Department of Radiation Oncology, Catharina Hospital, Michelangelolaan 2, 5623EJ, Eindhoven, The Netherlands.
authors.forename: Maurice
authors.initials: M
authors.lastname: van der Sangen
authors.affiliation: Department of Radiation Oncology, Catharina Hospital, Michelangelolaan 2, 5623EJ, Eindhoven, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: van Lieshout
authors.affiliation: Department of Radiation Oncology, Catharina Hospital, Michelangelolaan 2, 5623EJ, Eindhoven, The Netherlands.
authors.forename: Coen W
authors.initials: CW
authors.lastname: Hurkmans
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D058430:Humeral Head / Q000000981:diagnostic imaging / Q000528:radiation effects*; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000528:radiation effects*; D015182:Lymphatic Irradiation / Q000379:methods*; D058958:Organs at Risk / Q000528:radiation effects*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*
keywords: Breast radiotherapy; Humeral head; IMRT; Lymph nodes; Planning study; VMAT