PURPOSE: Radiation-induced cardiac toxicity is a potential lethal complication. The aim of this study was to assess whether there is a dose dependent relationship between radiation dose and myocardial fibrosis in patients that received neoadjuvant chemoradiation (nCRT) for esophageal cancer (EC).
MATERIALS AND METHODS: Forty EC patients treated with a transthoracic esophagectomy with (n=20) or without (n=20) nCRT (CROSS regimen) were included. Cardiovascular magnetic resonance (CMR) imaging (1.5 Tesla) for left ventricular (LV) function, late gadolinium enhancement (LGE) and T1 mapping were performed. Extracellular volume (ECV), as a surrogate for collagen burden, was measured for all LV segments separately. The dose-response relationship between ECV and mean radiation dose per LV myocardial segment was evaluated using mixed model analysis.
RESULTS: Seventeen nCRT and 16 control patients were suitable for analysis. Mean time after treatment was 67.6 ± 8.1 (nCRT) and 122 ± 35 (controls) months (p=0.02). In nCRT patients we found a significantly higher mean global ECV of 28.2% compared to 24.0% in controls (p<0.001). After nCRT, LV myocardial segments with elevated ECV had received significantly higher radiation doses. In addition, a linear dose-effect relation was found with a 0.136 percent point increase of ECV for each Gray (p<0.001). There were no differences in LV function measures and LGE between both groups.
CONCLUSION: Myocardial ECV was significantly higher in long term EC survivors after nCRT, as compared surgery only. Moreover, this ECV increase was linear with the radiation dose per LV segment, indicating radiation-induced myocardial fibrosis.
|Journal||International Journal of Radiation Oncology, Biology, Physics|
|Publication status||E-pub ahead of print - 9-Feb-2021|