title: Pulmonary function tests - an easy selection method for respiratory-gated radiotherapy in patients with left-sided breast cancer.
abstract: OBJECTIVE
  The purpose of this study was to establish a feasible and convenient method for selection of the subset of patients with left-sided breast cancer for whom respiratory-gated radiotherapy (RT) would be necessary to meet the national recommendation regarding radiation dose to the heart.
  
  
  METHODS
  The volume of heart receiving a dose equal to or higher than 25 Gy (V25Gy), the mean heart dose (Dmean) and total lung volume (TLV-CT) were obtained from treatment plans based on computer tomography (CT) series recorded during free breathing (FB), and the correlation between dose to the heart and TLV-CT was studied. Second, the correlation between TLV-CT and TLV defined from three pulmonary function tests (PFTs); spirometry, gas diffusion and plethysmograhy, was evaluated.
  
  
  RESULTS
  Dose to the heart (V25Gy and Dmean) decreased with increasing TLV-CT. Pearson's correlation coefficient (r) for TLV-CT versus V25Gy and Dmean was equal (r = -0.809, p < 0.01) for patients planned for tangential breast RT only, and r = -0.853 and -0.861 (p < 0.01) for patients planned for loco-regional RT. Regression analysis showed good correlation between TLV-CT and TLV calculated from pulmonary function tests (R(2) ≥ 0.717, p < 0.01).
  
  
  CONCLUSIONS
  TLV defined by routine pulmonary function tests can be used to identify the subset of left-sided breast cancer patients who require respiratory-gated RT.
authors.affiliation: Department of Hematology and Oncology, Stavanger University Hospital , Stavanger , Norway.
authors.forename: Mari H B
authors.initials: MH
authors.lastname: Hjelstuen
authors.forename: Ingvil
authors.initials: I
authors.lastname: Mjaaland
authors.forename: Johan
authors.initials: J
authors.lastname: Vikström
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Madebo
authors.forename: Kjell Ivar
authors.initials: KI
authors.lastname: Dybvik
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D005260:Female; D006801:Humans; D008875:Middle Aged; D058958:Organs at Risk / Q000528:radiation effects; D018579:Patient Selection; D012372:ROC Curve; D011832:Radiation Injuries / Q000517:prevention & control*; D011878:Radiotherapy / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted; D012129:Respiratory Function Tests / Q000379:methods*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D000069584:Unilateral Breast Neoplasms / Q000532:radiotherapy*