Prevalence of poor cardiac anatomy in carcinoma of the breast treated with whole-breast radiotherapy: reconciling modern cardiac dosimetry with cardiac mortality data
Authors
Evans, Suzanne B.Sioshansi, Shirin
Moran, Meena S.
Hiatt, Jessica
Price, Lori Lyn
Wazer, David E.
UMass Chan Affiliations
Department of Radiation OncologyDocument Type
Journal ArticlePublication Date
2012-12-01Keywords
AdultAged
Aged, 80 and over
Body Mass Index
Breast
Breast Neoplasms
Carcinoma
Coronary Artery Disease
Female
Heart
Humans
Middle Aged
Multivariate Analysis
Organ Size
Radiation Injuries
Radiotherapy Dosage
Neoplasms
Oncology
Metadata
Show full item recordAbstract
PURPOSE: : The purpose of the study was to identify patient characteristics that predict for increased cardiac exposure through dosimetric analysis of the anatomy of a cohort of women treated with left-sided tangential breast radiation. Statistical analyses estimations for the appropriate sample sizes required for detection of significant differences in cardiac mortality at 15 years were conducted, assuming a threshold V25 for radiation-induced coronary artery disease (CAD) beyond which women are at risk for radiation-induced coronary artery disease. METHODS AND MATERIALS: : Detailed heart dosimetry was recorded. Clinical factors (age, history of CAD, diabetes, receipt of cardiotoxic agents, weight/body mass index) and anatomic factors (heart volume, breast volume, cardiac contact distance) were recorded for each patient. RESULTS: : The average heart V25 was 3.57%. The median percentage of the heart included in the tangential beam was 4.02%. There were no clinical or anatomic factors that predict suboptimal heart anatomy (ie, V25 of >/=6%) on multivariate analysis. The sample size calculations using thresholds for induction of CAD of V25 >/=1%, 6%, and 10% yielded sample sizes of 1314, 9504, and 61,342, respectively; considering node-positive breast cancer mortality and 15% loss to follow-up, these change to 2237, 16,166, and 104,334, respectively. CONCLUSIONS: : Current studies with modern radiotherapy techniques would be underpowered to detect a difference in cardiac mortality where only some women are at risk. The heart, chest wall, and breast have a complex relationship to tangential breast radiation, and their interplay prevented this anatomic metric's success.Source
Am J Clin Oncol. 2012 Dec;35(6):587-92. doi: 10.1097/COC.0b013e31822d9cf6. Link to article on publisher's siteDOI
10.1097/COC.0b013e31822d9cf6Permanent Link to this Item
http://hdl.handle.net/20.500.14038/47916PubMed ID
21926900Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1097/COC.0b013e31822d9cf6