Late cardiac toxicity of neo-adjuvant chemoradiation in esophageal cancer survivors: A prospective cross-sectional pilot study.

PURPOSE: Although cure rates in esophageal cancer (EC) have improved since the introduction of neoadjuvant chemoradiation (nCRT), evidence for treatment-related cardiac toxicity is growing, of which the exact mechanisms remain unknown. The primary objective of this study was to identify (subclinical) cardiac dysfunction in EC patients after nCRT followed by surgical resection as compared to surgery alone. MATERIALS AND METHODS: EC survivors followed for 5-15 years after curative resection with (n = 20) or without (n = 20) nCRT were enrolled in this prospective cross-sectional pilot study. All patients underwent several clinical and diagnostic tests in order to objectify (sub)clinical cardiac toxicity including cardiac CT and MRI, echocardiography, ECG, 6-minutes walking test, physical examination and EORTC questionnaires. RESULTS: We found an increased rate of myocardial fibrosis (Linear late gadolinium enhancement (LGE) 4 vs. 1; p = 0.13; mean extracellular volume (ECV) 28.4 vs. 24.0; p < 0.01), atrial fibrillation (AF) (6 vs. 2; p = 0.07) and conduction changes in ECG among patients treated with nCRT as compared to those treated with surgery alone. The results suggested an impact on quality of life in terms of worse role functioning for this patient group (95.0 vs. 88.8; p = 0.03). CONCLUSION: Based on our analyses we hypothesize that in EC patients, radiation-induced myocardial fibrosis plays a central role in cardiac toxicity leading to AF, conduction changes and ultimately to decreased role functioning. The results emphasize the need to verify these findings in larger cohorts of patients.

Radiation-Induced Myocardial Fibrosis in Long-Term Esophageal Cancer Survivors.

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 who received neoadjuvant chemoradiation (nCRT) for esophageal cancer (EC). METHODS AND MATERIALS: Forty patients with EC treated with a transthoracic esophagectomy with (n = 20) or without (n = 20) nCRT (CROSS study regimen) were included. Cardiovascular magnetic resonance imaging (1.5 Tesla) for left ventricular (LV) function, late gadolinium enhancement, 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 a mixed-model analysis. RESULTS: Seventeen nCRT and 16 control patients were suitable for analysis. The mean time after treatment was 67.6 ± 8.1 (nCRT) and 122 ± 35 (controls) months (P = .02). In nCRT patients, we found a significantly higher mean global ECV of 28.2% compared with 24.0% in the controls (P < .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% point increase of ECV for each Gy (P < .001). There were no differences in LV function measures and late gadolinium enhancement between both groups. CONCLUSIONS: Myocardial ECV was significantly higher in long-term EC survivors after nCRT compared with surgery only. Moreover, this ECV increase was linear with the radiation dose per LV segment, indicating radiation-induced myocardial fibrosis.