| ObjectiveChest radiotherapy can increase the long-term risk of cardiac death in cancer survivors,so there is a need for early detection markers for early detection.Native T1 and T2 mapping can detect early myocardial damage from cancer-related treatment-induced cardiotoxicity.Therefore,this study aimed to confirm the native T1 and T2 values’ ability to detect and monitor early myocardial injury in oncology patients treated with chest radiotherapy.Materials and methodsFifteen participants received non-anthracycline chemotherapy and chest radiotherapy,and 30 age/sex-matched controls were included in this prospective study.Patients underwent Cardiac Magnetic Resonance(CMR)scans at 2 days,3 months,and 6 months after the end of chest radiotherapy,consisting mainly of Cine sequences,native T1 mapping and T2 mapping sequences at the four-chamber,three-chamber,two-chamber,and short-axis levels.Image postprocessing was performed using CVl42 software.The myocardium was divided into 16 segments according to the American Heart Association(AHA)1 6-segment method,and image analysis was performed using the following four modules:1)Short-axis 3D module,using cine sequences,to obtain 19 quantitative parameters related to left ventricular function;2)Strain module using cine sequences,to obtain 24 quantitative parameters related to myocardial strain;3)Tissue T1 mapping module,using Native T1 mapping sequences,to measure myocardial native T1 values in the whole myocardium as well as in the irradiated and non-irradiated fields;4)Tissue T2 mapping module,using T2 mapping sequences,to measure myocardial native T1 values in the whole myocardium as well as in the irradiated and non-irradiated fields myocardial T2 values in the irradiated and non-irradiated fields.Differences between baseline and control groups were compared using Student’s t-test or Mann-Whitney U-test.Data were compared among baseline and follow-ups by using the Friedman rank test with post hoc test with Bonferroni correction.Differences in variables between irradiated areas(IA)and non-irradiated areas(NIA)were compared using paired samples t-tests.ResultsThere were no significant differences in left ventricular function,native T1,T2,and strain between patients and controls before chest radiotherapy.In 15 participants who were followed up for 6 months,there was a significant change only in LVEF among baseline and the first follow-up(P=0.021),while the adjusted P value was higher than 0.05 after Bonferroni correction,as well as other parameters.Native T1 values were elevated at 3 months and 6 months in irradiated areas compared with baseline(1288.72 msec± 66.59 vs 1212.51 msec±45.41;1348.01 msec ±54.16 vs 1212.51 msec ±45.41;P<0.001 for both).But T2 values only changed at 3 months in irradiated areas compared with baseline(44.21 msec± 3.35 vs 39.14 msec±1.44;P=0.006).Neither the native T1 nor T2 values changed in nonirradiated areas during the follow-up period(all P>0.05).There were no significant differences in strain changes during the follow-up period(all P>0.05).Conclusions(1)Native T1 values in the irradiated field were consistently higher at 3 and 6 months after chest radiotherapy,possibly associated with early edema and late fibrosis of cardiomyocytes;(2)Elevated T2 values in the irradiated field at 3 months after chest radiotherapy,recovered to baseline levels at 6 months,possibly associated with the appearance of early edema,the resolution of late edema,and fibrosis of cardiomyocytes;(3)Left ventricular function and the global strain showed no significant changes during the 6month follow-up period,probably due to the fact that the participants had only local myocardial involvement,so no significant changes in global cardiac function occurred.In conclusion,native T1 and T2 mapping can detect early changes in the myocardium at 3 months after chest radiotherapy,which is earlier than LVEF and the global strain.This may provide clinical evidence of the time point to early prevent cardiac injury during chest radiotherapy. |
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