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Beaton L, Bergman A, Nichol A, Aparicio M, Wong G, Gondara L, Speers C, Weir L, Davis M, Tyldesley S. Cardiac death after breast radiotherapy and the QUANTEC cardiac guidelines. Clin Transl Radiat Oncol 2019; 19:39-45. [PMID: 31485490 PMCID: PMC6715791 DOI: 10.1016/j.ctro.2019.08.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/11/2019] [Indexed: 02/08/2023] Open
Abstract
Cardiovascular risk factors predict for cardiac death after breast radiotherapy. Cardiovascular risk factors should be modified in breast cancer patients. Radiation induced cardiac death at 10-years is low if mean heart dose is <3.3 Gy. Radiation induced cardiac death at 10-years is low if maximum LAD dose is <45.4 Gy. Studies are needed to evaluate heart and LAD constraints in the CT-planning era.
Background Breast/chest wall irradiation (RT) increases risk of cardiovascular death. International Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) guidelines state for partial heart irradiation a “V25Gy <10% will be associated with a <1% probability of cardiac mortality” in long-term follow-up after RT. We assessed whether women treated with breast/chest wall RT 10-years ago who died of cardiovascular disease (CVD) violated QUANTEC guidelines. Materials/methods A population-based database identified all cardiovascular deaths in women with early-stage breast cancer <80 years, treated with adjuvant breast/chest wall RT from 2002 to 2006. Ten-year rate of cardiovascular death was calculated using a Kaplan-Meier method. Patients were matched on a 2:1 basis with controls that did not die of CVD. For left-sided cases, the heart and left anterior descending (LAD) artery were retrospectively delineated. Dose-volume histograms were calculated, and heart V25Gy compared to QUANTEC guidelines. Results 5249 eligible patients received breast/chest wall RT from 2002 to 2006: 76 (1.4% at 10-years) died of CVD by June 2015. Forty-two patients received left-sided RT (1.7% CVD death at 10-years), 34 right-sided RT (1.3% at 10-years). Heart V25Gy did not exceed 10% in any left-sided cases. No cardiac dosimetry parameter distinguished left-sided cases from controls. Conclusions QUANTEC guidelines were not violated in any patient that died of CVD after left-sided RT. The risk of radiation induced cardiac death at 10-years appears to be very low if MHD is <3.3 Gy and maximum LAD dose (EQD23 Gy) is <45.4 Gy. Further studies are needed to evaluate heart and LAD constraints in the CT-planning era.
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Affiliation(s)
- Laura Beaton
- Department of Radiation Oncology, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada
| | - Alanah Bergman
- Department of Medical Physics, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada
| | - Alan Nichol
- Department of Radiation Oncology, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada.,Breast Cancer Outcomes Unit, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Maria Aparicio
- Department of Radiation Oncology, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada
| | - Graham Wong
- Department of Cardiology, Vancouver General Hospital, Vancouver, British Columbia, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lovedeep Gondara
- Breast Cancer Outcomes Unit, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada
| | - Caroline Speers
- Breast Cancer Outcomes Unit, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada
| | - Lorna Weir
- Department of Radiation Oncology, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada.,Breast Cancer Outcomes Unit, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Margot Davis
- Department of Cardiology, Vancouver General Hospital, Vancouver, British Columbia, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Scott Tyldesley
- Department of Radiation Oncology, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada.,Breast Cancer Outcomes Unit, BC Cancer Agency, Vancouver Centre, Vancouver, British Columbia, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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