title: Active Breathing Coordinator reduces radiation dose to the heart and preserves local control in patients with left breast cancer: report of a prospective trial.
abstract: OBJECTIVE
  Incidental radiation dose to the heart and lung during breast radiation therapy (RT) has been associated with an increased risk of cardiopulmonary morbidity. We conducted a prospective trial to determine if RT with the Active Breathing Coordinator (ABC) can reduce the mean heart dose (MHD) by ≥20% and dose to the lung.
  
  
  METHODS
  Patients with stages 0-III left breast cancer (LBC) were enrolled and underwent simulation with both free breathing (FB) and ABC for comparison of dosimetry. ABC was used during the patient's RT course if the MHD was reduced by ≥5%. The median prescription dose was 50.4 Gy plus a boost in 77 patients (90%). The primary endpoint was the magnitude of MHD reduction when comparing ABC to FB. Secondary endpoints included dose reduction to the heart and lung, procedural success rate, and adverse events.
  
  
  RESULTS
  A total of 112 patients with LBC were enrolled from 2002 to 2011 and 86 eligible patients underwent both FB and ABC simulation. Ultimately, 81 patients received RT using ABC, corresponding to 72% procedural success. The primary endpoint was achieved as use of ABC reduced MHD by 20% or greater in 88% of patients (P < .0001). The median values for absolute and relative reduction in MHD were 1.7 Gy and 62%, respectively. RT with ABC provided a statistically significant dose reduction to the left lung. After a median follow up of 81 months, 8-year estimates of locoregional relapse, disease-free, and overall survival were 7%, 90%, and 96%, respectively.
  
  
  CONCLUSIONS
  ABC was well tolerated and significantly reduced MHD while preserving local control. Use of the ABC device during RT should be considered to reduce the risk of ischemic heart disease in populations at risk.
authors.affiliation: Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania. Electronic address: harrieteldredge@gmail.com.
authors.forename: Harriet
authors.initials: H
authors.lastname: Eldredge-Hindy
authors.affiliation: Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Virginia
authors.initials: V
authors.lastname: Lockamy
authors.affiliation: Department of Biostatistics, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Albert
authors.initials: A
authors.lastname: Crawford
authors.affiliation: Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Virginia
authors.initials: V
authors.lastname: Nettleton
authors.affiliation: Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Maria
authors.initials: M
authors.lastname: Werner-Wasik
authors.affiliation: Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Joshua
authors.initials: J
authors.lastname: Siglin
authors.affiliation: Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Simone
authors.affiliation: Department of Radiation Oncology, Duke University, Durham, North Carolina.
authors.forename: Kulbir
authors.initials: K
authors.lastname: Sidhu
authors.affiliation: Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Pramila R
authors.initials: PR
authors.lastname: Anne
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006321:Heart / Q000528:radiation effects*; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D011874:Radiometry; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D018714:Radiotherapy, Adjuvant; D012119:Respiration; D015656:Respiratory Mechanics / Q000502:physiology*