KEY TAKEAWAYS
- The study aimed to investigate the dose-risk relationships between near-Dmax to RCA and LAD and IHD mortality after BC RT.
- Researchers noticed that the RCA and LAD doses independently predict long-term cardiotoxicity after BC RT.
Doses to the coronary arteries during breast cancer (BC) radiotherapy (RT) are believed to correlate with long-term cardiac toxicity post-treatment.
Mats Perman and the team aimed to examine the association between near maximum doses (Dmax) delivered to the right coronary artery (RCA) and left anterior descending coronary artery (LAD) and the incidence of ischemic heart disease (IHD) mortality following BC RT.
They performed an inclusive analysis on a cohort of 2,813 women diagnosed with BC between 1958 and 1992, with a follow-up of at least 10 years. They identified 134 cases of death due to IHD occurring 10-19 years after breast cancer diagnosis. For each case, one control was selected from the cohort matched for age at diagnosis. The study obtained 3D-volume and 3D-dose reconstructions from individual radiotherapy charts.
Researchers estimated the near Dmax to the RCA and the LAD, also the mean heart dose (MHD). Conditional logistic regression analysis was performed, comparing piecewise spline transformation and simple linear modeling for the best fit.
The linear dose-risk relationship was observed for both the near Dmax to the RCA (OR/Gray [Gy] 1.03 [1.01-1.05]) and the LAD (OR/Gy 1.04 [1.02-1.06]) in a multivariable model. A linear dose-risk relationship was also found for MHD (OR/Gy 1.14 [1.08-1.19]). Simple linear modeling outperformed spline transformations for all relationships.
The study concluded that doses to both the RCA and LAD independently predict long-term cardiotoxicity following radiotherapy for breast cancer. Additionally, the RCA and the LAD should be considered organs at risk during radiotherapy planning.
No funding information was provided.
Source: https://pubmed.ncbi.nlm.nih.gov/38682458/
Perman M, Johansson KA, Holmberg E, et al. (2024). “Doses to the right coronary artery and the left anterior descending coronary artery and death from ischemic heart disease after breast cancer radiotherapy: a case-control study in a population-based cohort.” Acta Oncol. 2024 Apr 29;63:240-247. doi: 10.2340/1651-226X.2024.19677. PMID: 38682458.
