title: Unintended cardiac irradiation during left-sided breast cancer radiotherapy.
abstract: OBJECTIVE
  Cardiac irradiation during left-sided breast radiotherapy may lead to deleterious cardiac side effects. Using image guided radiotherapy, it is possible to exclude the heart from treatment fields and monitor reproducibility of virtual simulation (VS) fields at treatment delivery using electronic portal imaging (EPI). Retrospectively, we evaluate the incidence of cardiac irradiation at VS and subsequent unintended cardiac irradiation during treatment.
  
  
  METHODS
  Patients receiving left-sided radiotherapy to the breast or chest wall, treated with a glancing photon field technique during a four-month period, were included. VS images and EPIs during radiotherapy delivery were visually assessed. The presence of any portion of the heart within the treatment field at VS or during treatment was recorded. Central lung distance and maximum heart distance were recorded.
  
  
  RESULTS
  Of 128 patients, 45 (35.1%) had any portion of the heart within the planned treatment field. Of these, inclusion of the heart was clinically unavoidable in 25 (55.6%). Of those with no heart included in the treatment fields at VS, 41 (49.4%) had presence of the heart as assessed on EPI during treatment.
  
  
  CONCLUSIONS
  Unintended cardiac irradiation during left-sided breast radiotherapy treatment occurs in a sizeable proportion of patients.
  
  
  CONCLUSIONS
  Despite the use of three-dimensional computed tomography simulation and cardiac shielding, sizeable proportions of patients receiving left-sided breast cancer radiotherapy have unintended cardiac irradiation.
authors: Department of Clinical Oncology, Cancer Centre, Belfast City Hospital, Belfast, Northern Ireland, UK. rebecca.b.goody@gmail.com
authors: R B
authors: RB
authors: Goody
authors: J
authors: J
authors: O'Hare
authors: K
authors: K
authors: McKenna
authors: L
authors: L
authors: Dearey
authors: J
authors: J
authors: Robinson
authors: P
authors: P
authors: Bell
authors: J
authors: J
authors: Clarke
authors: J J A
authors: JJ
authors: McAleer
authors: J M
authors: JM
authors: O'Sullivan
authors: G G
authors: GG
authors: Hanna
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000532:radiotherapy*; D018567:Breast Neoplasms, Male / Q000532:radiotherapy; D005260:Female; D006321:Heart / Q000528:radiation effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology*; D011835:Radiation Protection; D012189:Retrospective Studies
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