title: Lung dose-volume parameters and the risk of pneumonitis for patients treated with accelerated partial-breast irradiation using three-dimensional conformal radiotherapy.
abstract: OBJECTIVE
  There are no data on how complication rates after accelerated partial-breast irradiation delivered by three-dimensional conformal radiotherapy are affected by treatment technique. We therefore examined the risk of pneumonitis in relation to lung dose-volume parameters.
  
  
  METHODS
  Our prospective dose-escalation trial enrolled 198 treated patients from 2003 to 2007. Patients received 32 or 36 Gy in 4-Gy fractions, given twice daily: 29 (14%) were treated with pure photons; 149 (77%) with mixed photons and electrons; and 20 (10%) with protons.
  
  
  RESULTS
  There were four cases of pneumonitis at 4, 4, 7, and 9 months after treatment. All were in the 36-Gy cohort and were treated with pure photons. The risk of pneumonitis for the two cohorts combined was: 17% (four of 24) for an ipsilateral lung volume (ILV) receiving 20 Gy or higher (ILV, 20 Gy) of 3% or higher (P = .0002 for comparison to ILV 20 Gy < 3%, Fisher's exact test); 20% (four of 20) for an ILV 10 Gy of 10% or higher (P = .0001); and 15% (four of 26) for an ILV 5 Gy of 20% or higher (P = .0002).
  
  
  CONCLUSIONS
  The risk of pneumonitis appeared related to the ILV treated. This volume can be reduced by using mixed photons and electron when possible. We recommend that the ILV 20 Gy should be lower than 3%, the ILV 10 Gy lower than 10%, and the ILV 5 Gy lower than 20% when purely coplanar techniques are used.
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Radiation Oncology, Boston MA 02215, USA. arecht@bidmc.harvard.edu
authors.forename: Abram
authors.initials: A
authors.lastname: Recht
authors.forename: Marek
authors.initials: M
authors.lastname: Ancukiewicz
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Alm El-Din
authors.forename: Xing-Qi
authors.initials: XQ
authors.lastname: Lu
authors.forename: Chrystalla
authors.initials: C
authors.lastname: Martin
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Berman
authors.forename: Ariel E
authors.initials: AE
authors.lastname: Hirsch
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Kachnic
authors.forename: Angela
authors.initials: A
authors.lastname: Katz
authors.forename: Shannon
authors.initials: S
authors.lastname: MacDonald
authors.forename: Elena A
authors.initials: EA
authors.lastname: Nedea
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Stevenson
authors.forename: Simon N
authors.initials: SN
authors.lastname: Powell
authors.forename: Alphonse G
authors.initials: AG
authors.lastname: Taghian
mesh_terms: D001940:Breast / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008168:Lung / Q000528:radiation effects*; D008875:Middle Aged; D011014:Pneumonia / Q000209:etiology*; D011446:Prospective Studies; D011829:Radiation Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects*