title: How Important Is a Reproducible Breath Hold for Deep Inspiration Breath Hold Breast Radiation Therapy?
abstract: OBJECTIVE
  Deep inspiration breath hold (DIBH) for left-sided breast cancer has been shown to reduce heart dose. Surface imaging helps to ensure accurate breast positioning, but it does not guarantee a reproducible breath hold (BH) at DIBH treatments. We examine the effects of variable BH positions for DIBH treatments.
  
  
  METHODS
  Twenty-five patients who underwent free breathing (FB) and DIBH scans were reviewed. Four plans were created for each patient: FB, DIBH, FB_DIBH (the DIBH plans were copied to the FB images and recalculated, and image registration was based on breast tissue), and P_DIBH (a partial BH with the heart shifted midway between the FB and DIBH positions). The FB_DIBH plans give a "worst-case" scenario for surface imaging DIBH, where the breast is aligned by surface imaging but the patient is not holding their breath. Kolmogorov-Smirnov tests were used to compare the dose metrics.
  
  
  RESULTS
  The DIBH plans gave lower heart dose and comparable breast coverage versus FB in all cases. The FB_DIBH plans showed no significant difference versus FB plans for breast coverage, mean heart dose, or maximum heart dose (P≥.10). The mean heart dose differed between FB_DIBH and FB by <2 Gy for all cases, and the maximum heart dose differed by <2 Gy for 21 cases. The P_DIBH plans showed significantly lower mean heart dose than FB (P<.01). The mean heart doses for the P_DIBH plans were <FB for 22 cases, the maximum dose was <FB for 18 cases.
  
  
  CONCLUSIONS
  A DIBH plan delivered to a FB patient setup with surface imaging will yield dosimetry similar to that of a plan created and delivered FB. A DIBH plan delivered with even a partial BH can give reduced heart dose compared with FB techniques.
authors.affiliation: Cone Health Cancer Center, Greensboro, North Carolina. Electronic address: David.wiant@conehealth.com.
authors.forename: David
authors.initials: D
authors.lastname: Wiant
authors.affiliation: Cone Health Cancer Center, Greensboro, North Carolina.
authors.forename: Stacy
authors.initials: S
authors.lastname: Wentworth
authors.affiliation: Cone Health Cancer Center, Greensboro, North Carolina.
authors.forename: Han
authors.initials: H
authors.lastname: Liu
authors.affiliation: Cone Health Cancer Center, Greensboro, North Carolina.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Sintay
mesh_terms: D001940:Breast / Q000528:radiation effects; D062485:Breath Holding; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000528:radiation effects*; D006801:Humans; D001239:Inhalation; D015412:Mastectomy, Segmental; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D011859:Radiography; D011880:Radiotherapy Planning, Computer-Assisted; D015203:Reproducibility of Results; D012119:Respiration; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D000069584:Unilateral Breast Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*