25 Review on cardiac toxicity or without symptomatic cardiac toxicity, respectively. No associations were found between cardiac toxicity and medical history, surgery or decreased FDG uptake of the myocardium. In contrast, Jingu et al. found increased FDG uptake within the irradiated field after a median time of 9.3 months after treatment for esophageal cancer. In a prospective study, 8 patients underwent additional ultrasound, MRI and myocardial SPECT to investigate the state of metabolism and vascular flow in the myocardium. The SPECT studies suggested microvascular damage and impairment in perfusion and fatty acid metabolism; under these ischemic conditions, glucose metabolism increases. MRI scans with gadolinium showed delayed enhancement in only 2 patients and was thought to be relatively insensitive to myocardial damage. Hatahenaka et al. reported on the results obtained in 31 patients treated with chemoradiation.[13] Patients were subjected to cardiac MRIs before, during and shortly after therapy. Patients were divided into a low left ventricle dose group (mean LV dose of 0.33 Gy, predominantly upper and middle esophageal tumors), and a high dose group with a mean dose of 18.1 Gy. The LV ejection fraction (LVEF), LV end diastolic volume index and left ventricular stroke index were significantly lower after treatment, which was also the case for wall motion disorders in segments 8, 9 and 10. The heart rate was significantly higher after treatment. In the low dose group, only LVEF was decreased, suggesting a role for cisplatinum. In conclusion, these five imaging studies showed early wall motion disorders and reduced or increased uptake within the irradiated area on different imaging modalities, which indicates a local effect in the myocardium. Changes in the metabolism of the irradiated areas may explain these effects. Discussion This review was undertaken to evaluate the current evidence on the types and incidence of radiation induced cardiac toxicity after multimodality treatment for esophageal cancer, in order to improve radiotherapy treatment decision making. The incidence of clinically relevant cardiac complications was reported in 6 out of 10 reviewed papers. The overall crude incidence was 10.8 % (range: 5%-44%). Most events occurred within 2 years after treatment. Given the low overall survival rate of 3 years, the actuarial incidence rate for cardiac complications is expected to be much higher. 2
RkJQdWJsaXNoZXIy MTk4NDMw