title: Impact of post-operative radiation on coronary arteries in patients of early breast cancer: A pilot dosimetric study from a tertiary cancer care center from India.
abstract: BACKGROUND
  The significant impact of postoperative radiotherapy (PORT) on cardiac morbidity in patients of early breast cancer (EBC) undergoing breast-conserving surgery has been shown in different studies. The present study was conducted to assess the impact of surgery and the side of involvement on radiation dose to left anterior descending artery (LAD) and Left circumflex coronary artery (LCx).
  
  
  METHODS
  Totally, 58 patients of EBC were randomly chosen for this dosimetric study and planned with tangential field technique without intensity modulation (IM). Heart, LAD, and LCx (n = 55) were contoured. Dose volume histograms were analyzed to determine the Dmax (maximum dose) and Dmean (mean dose) of LAD and LCx. Student's t-test was used for comparative analysis of the means.
  
  
  RESULTS
  The mean Dmax of LAD for left (L) EBC was 3.17 Gray (Gy) while for right (R) EBC it was 0.86 Gy (P = 0.007; 95% C.I, 1.14-3.48). The mean Dmean of LAD for L-EBC and R-EBC were 1.97 Gy and 0.79 Gy, respectively (P = 0.029; 95% C.I, 0.77-1.60). The mean-Dmax of LCx for patients with L-EBC (2.9 Gy; range: 1.2-4.35 Gy) was statistically higher than that for R-EBC (1.3 Gy; range: 0.7-3.2 Gy) (P = 0.045). The mean-Dmean of LCx for L-EBC (2.1 Gy; range: 0.6-3.6 Gy) was also significantly higher than that of L-EBC (0.9 Gy; range: 0.7-2.1 Gy) (P = 0.03). There was no significant impact of the pattern of surgery on LAD dose, but significance was noted for LCx dose parameters (P = 0.04 and 0.08 for m-Dmax and m-Dmean of LCx).
  
  
  CONCLUSIONS
  This pilot dosimetric study confirms the assumption that patients with left-sided EBC are at higher risk of developing long-term cardiac morbidity when treated with PORT due to increased dose to LAD.
authors.forename: S
authors.initials: S
authors.lastname: Roy
authors.affiliation: Department of Radiation Oncology, All Institute of Medical Sciences, New Delhi, India.
authors.forename: D
authors.initials: D
authors.lastname: Mondal
authors.forename: W
authors.initials: W
authors.lastname: Melgandi
authors.forename: M
authors.initials: M
authors.lastname: Jana
authors.forename: K K
authors.initials: KK
authors.lastname: Chowdhury
authors.forename: S
authors.initials: S
authors.lastname: Das
authors.forename: K P
authors.initials: KP
authors.lastname: Haresh
authors.forename: S
authors.initials: S
authors.lastname: Gupta
authors.forename: D
authors.initials: D
authors.lastname: Sharma
authors.forename: P K
authors.initials: PK
authors.lastname: Julka
authors.forename: G K
authors.initials: GK
authors.lastname: Rath
mesh_terms: D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology* / Q000528:radiation effects; D005260:Female; D006331:Heart Diseases / Q000209:etiology / Q000401:mortality* / Q000473:pathology*; D006801:Humans; D007194:India; D015412:Mastectomy, Segmental; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D011881:Radiotherapy, Computer-Assisted / Q000009:adverse effects; D015898:Tomography Scanners, X-Ray Computed