Cardiotoxicity is a well-recognized, serious adverse effect of thoracic radiation therapy. This study aimed to evaluate longitudinal electrocardiogram (ECG) changes in patients receiving thoracic radiation therapy and identify correlating factors that can predict the risk of cardiotoxicity. This retrospective study included 202 patients treated with thoracic radiation therapy, and chemotherapy and targeted therapy were allowed. Mean heart dose (MHD) was evaluated on dose-volume histograms. ECG, high-sensitivity cardiac troponin T (hs-cTnT), and N-terminal B-type natriuretic peptide (NT-proBNP) analyses were conducted before irradiation and during the follow-up period of 6–12 months (average 8 months). Chi square test and logistic regression analysis were applied to identify risk factors associated with ECG changes. At a median time of 3 months postirradiation, 46.5% of patients showed ECG changes, and 33.0% of patients achieved baseline ECG levels during the follow-up period at a median of 5 months postirradiation. Logistic regression analysis identified MHD, hs-cTnT and NT-pro BNP as significant factors associated with ECG changes (P < 0.05). Hs-cTnT and NT-proBNP were increased significantly after radiation therapy compared with baseline levels (P < 0.05), and these increases were observed as a median time of 2 months postirradiation, which was earlier than ECG changes. Higher MHD and elevated hs-cTnT and NT-proBNP levels correlated with an increased risk of ECG changes in patients receiving thoracic radiation therapy. Early identification of patients at high risk of cardiotoxicity and timely intervention might reduce the incidence of radiation-induced cardiac toxicity.
INTRODUCTION
Radiation therapy (RT) is a major modality in cancer treatment, with over half of all cancer patients receiving radiation at some point in the course of treatment (1). Accumulating clinical evidence demonstrates that years after exposure to thoracic radiation, a large number of patients are at an increased risk of developing cardiac disease due to incidental dose delivery to the heart, which has negative effects on patients' quality of life and even increases mortality (2–4). Advances in modern radiation therapy technology have made radiation delivery more precise. However, numerous studies have shown that the risk of radiation-induced heart disease (RIHD) has not been eliminated (5, 6). For example, breast cancer patients were found to have an approximately 4–16% relative increase in heart disease and/or major coronary events for each 1 Gy in mean heart dose (MHD) received (7, 8).
Electrocardiography (ECG) is widely used in the clinical screening and monitoring of cardiotoxicity associated with systemic cancer therapies (9). Most prior cardiotoxicity studies focused on breast cancer patients receiving chemotherapy or targeted therapy. Advances in chemotherapy and targeted therapy have led to an improvement in cancer survival rates, but at a cost of higher cardiac side effects (9). Studies from western countries have reported the incidence of cancer treatment-induced cardiotoxicity for several chemotherapies and targeted therapies, including 1–57% for anthracycline, 2–28% for cyclophosphamide, 0–28% for trastuzumab, and 2–11% for bevacizumab (10–13). Cardiotoxicity associated with chemotherapy or targeted therapies mainly includes cardiac systolic dysfunction, cardiac ischemia, arrhythmias, pericarditis and repolarization abnormalities (14). A meta-analysis showed that the incidence of ECG abnormalities related to antitumor treatment was about 11%, and the most common ECG abnormality is related to anthracycline therapy (15). Although the long-term effects of cardiac radiation are relatively well known, the acute effects, if any, are not. Most studies have explored the long-term effects of radiation-induced cardiotoxicity among survivors of Hodgkin lymphoma or breast cancer (2, 16–18). To date, few studies have evaluated the acute effects of radiation on the heart, particularly early cardiac toxicity assessed using ECG (19, 20). In addition, most previous studies involved exposure of large portions of the heart to low dose radiation. With the emergence of modern conformal radiation technologies, the dose distributions to the heart can differ substantially, which may affect the change in ECG results after treatment to a certain extent.
Although advances in modern radiation technology have reduced the incidence of cardiotoxicity, current evidence demonstrates that the risk of cardiotoxicity remains (21). Therefore, greater knowledge of risk factors for radiation-induced cardiotoxicity is needed. Numerous previous studies assessed the effects of age, MHD, heart disease, hypertension, hyperglycemia, hyperlipidemia, and smoking on cardiotoxicity caused by radiation (2, 8, 22, 23). Moreover, early changes in conventional cardiac biomarkers after irradiated can aid in the detection of subclinical cardiotoxicity and play an important role in risk prediction. Some studies have evaluated the value of biomarkers including cardiac troponins and natriuretic peptides for predicting the risk of cardiotoxicity in patients treated with thoracic radiation therapy (19, 24, 25). The relationship between ECG changes after radiation therapy and survival prognosis has been confirmed by a study, they found evidence of associations between higher all-cause death rate and conduction or ischemic/pericarditis-like changes on ECG (26). However, few studies have investigated the ability of ECG changes after radiation therapy combined with these factors to predict the risk of cardiotoxicity.
The purpose of the present study was to evaluate the changes in ECG among patients who received radiation therapy for thoracic malignancies and then to identify risk factors significantly associated with cardiotoxicity based on ECG changes. This knowledge could allow us to identify patients at high risk for RIHD, enabling the application of targeted interventions that prevent or reverse RIHD.
MATERIALS AND METHODS
Study Population
This study was approved by the ethics committee of Shandong Cancer Hospital. We retrospectively enrolled patients with lung cancer, esophageal cancer, breast cancer and thymic cancer who received thoracic radiation therapy. Patients were enrolled from January 2021 to March 2022. The study included 202 patients who underwent ECG examination before and after treatment. Patients were included regardless of exposure to concurrent chemotherapy, sequential chemotherapy, immunotherapy, or targeted therapy. Patients were excluded if they did not complete the radiation treatment plan for any reason. ECG and biomarker measurements were collected every 1–2 months postirradiation, and the follow-up period was 6–12 months (average 8 months). The changes of ECG and biomarker of individual patients from pre-treatment to post-treatment are presented in Supplementary Table 1 (rare-199-04-01_s01.docx) ( https://doi.org/10.1667/RADE-22-00135.1.S1).2
Treatment Method
All patients were treated with intensity-modulated radiation therapy (IMRT). Among these patients, 9.4% received radiation therapy alone, while 90.6% received sequential chemotherapy or concurrent chemotherapy. A 3-dimensional or 4-dimensional computed tomography (CT) scan was obtained for radiation treatment planning, and when available, diagnostic CT and/or positron emission tomography scans were coregistered to the planning CT to aid delineation of tumor and normal anatomy structures. Radiation was targeted to the gross tumor and/or areas most at risk for microscopic tumor and was typically delivered in daily fractions (treatments) of 1.5–3.0 Gy to cumulative doses of 40.0–70.0 Gy. Radiotherapy was planned using Eclipse 13.5 (Varian Medical Systems) with prioritization of achieving the prescribed dose to the tumor while minimizing the dose to the spinal cord, lung, and heart. The dose distribution met the requirement that the planning target volume received 95% of the prescribed dose. A dose-volume histogram was rebuilt, and the MHD was estimated on the dose–volume histogram in the treatment-planning system.
ECG Analysis
ECG measurements were obtained with 12-lead devices at baseline and during the follow-up period after irradiation. The ECG characteristics analyzed by cardiologists included normal ECG, arrhythmic (sinus bradycardia, sinus tachycardia, atrial fibrillation, atrioventricular block, and left or right bundle branch block), ischemic [ST changes (ST depression and ST elevation) and T-wave changes (T-wave decline and T-wave inversion), and non-specific (left/right axis deviation, low voltage QRS, poor R wave progression, atrial enlargement, and prolonged/short QT interval)] parameters. Subsequent ECGs were then analyzed to determine whether any acute changes occurred after irradiation compared with baseline. Any new changes compared to baseline were considered ECG abnormalities.
Cardiac Biomarker Measurement
In this study, we evaluated the changes in the levels of biomarkers reflective of myocardial injury before and after treatment. We measured high-sensitivity cardiac troponin T (hs-cTnT) as a sensitive indicator of myocardial injury and N-terminal pro-B-type natriuretic peptide (NT-proBNP) as an indicator of left ventricular function and heart failure. The detection limit for Hs-cTnT in this study was 3 pg/ml, and the detection limit for NT-proBNP was 5 pg/ml.
Baseline Cardiovascular Events
An in-depth review of the patients' medical records was performed to determine the presence (or absence) of pre-existing cardiovascular disease (CVD). Hypertension, diabetes mellitus and heart disease (coronary artery disease, myocardial infarction, myocardial ischemia, and arrhythmia) were categorized as CVD. Past medical history, notes (consultation, follow-up, emergency department visits, and admissions), reports (imaging and ECG), and laboratory data were reviewed to identify prior diagnoses and cardiovascular events (coronary artery disease, myocardial ischemia and myocardial infarction).
Statistical Analysis
Standard descriptive statistics were used to characterize the study population at baseline using the proportion for categorical variables and the median or interquartile range (IQR) for nonnormally distributed continuous variables. We first investigated which risk factors were significantly associated with ECG changes. Factors considered for analysis included age, gender, tumor type, MHD, CVD, chemotherapy, smoking, and elevation of hs-cTnT and NT-proBNP levels. The risk factors involved in this study were categorical variables. Each variable was included in the univariate analysis using the Chi square test. If a variable presented with P < 0.2, that variable was considered a candidate predictor. These variables were then included in the logistic regression model. Variables with P < 0.05 were considered risk factors. The Mann-Whitney rank sum test was used to compare the difference in cardiac dose distribution between the ECG change group and non-ECG change group. Proportions of patients with ECG changes after irradiation in different subgroups were calculate using the chi square test. Differences in biomarker levels pre-irradiation and after completion of irradiation were tested with the Wilcoxon signed-rank test. Elevations above baseline of 30% and more than 1 pg/ml were considered clinically significant in this study. The proportions of patients with >30% increases in hs-cTnT and NT-proBNP were calculated at different time points after irradiation. A two-sided alpha level of 0.05 was used to assess statistical significance. All analyses were performed using SPSS version 23.0.
RESULTS
ECG Changes after Radiation Exposure
The characteristics of the patients enrolled in this study are summarized in Table 1. Baseline cardiac events were common in this patient population. Among the 202 patients, 55.9% experienced ECG abnormalities before radiation exposure. ECG changes after exposure occurred in 94 patients (46.5%; Table 2), with the most common changes being arrhythmias (26.6%), T-wave changes (25.5%), poor R-wave progression (17.0%), and ST changes (13.8%). Figure 1 shows representative ECG changes before and after RT. ECG changes were observed at various times after exposure, ranging from 1–10 months, with a median time of 3 months. Four patients with sinus tachycardia developed palpitations, and two patients with atrial fibrillation developed palpitations and chest tightness after exposure. In 31 of the 94 patients (33.0%), ECG values returned to the baseline levels within 3–9 months postirradiation, with a median time of 5 months.
TABLE 1
Patient Characteristics (n = 202)
TABLE 2
Summary of Electrocardiographic Changes after Irradiation (n = 94)
FIG. 1
Representative ECG results for a lung cancer patient (66 years old) who received radiation only and had no pre-existing cardiovascular disease. Typical ECG changes before (panel A) and after (panel B) irradiation. ST decline developed in leads II, III, aVF and V4-V6. Sinus tachycardia was evident after irradiation. The ECG recordings were obtained with a 25 mm/s speed.
Multivariate Analysis Based on ECG Changes
The univariate analysis showed that ECG abnormality was correlated with MHD, gender, CVD, hs-cTnT, and NT-proBNP (P < 0.2), and these factors were then included in the multivariate logistic regression analysis. Multivariate logistic regression analysis identified higher MHD and elevated hs-cTnT and NT-proBNP level as significant risk factors for ECG changes (Table 3), whereas gender and CVD were not significant risk factors. A higher MHD (≥5.0 Gy) was significantly associated with a higher risk of ECG changes, with an odds ratio (OR) of 2.037 [95% confidence interval (CI): 1.109–3.738, P = 0.022]. In addition, patients with an elevated hs-cTnT level (OR: 2.728; 95% CI: 1.039–7.167, P = 0.042) or NT-proBNP level (OR: 4.005; 95% CI: 1.199–13.383, P = 0.024) were at increased risk for ECG changes.
TABLE 3
Logistic Regression Analysis of Risk Factors for ECG Changes
MHD and ECG Changes
Figure 2 shows the differences in dose-distribution between patients who experienced ECG changes (ECG change group) and those who did not (non-ECG change group). The MHD differed significantly between the two groups (P = 0.014), and the median [interquartile range (IQR)] MHD in patients with ECG changes (7.6 Gy, 3.2–12.7 Gy) was higher than that in patients without ECG changes (4.3 Gy, 2.3–10.8 Gy), indicating that the MHD was a significant risk factor for ECG changes in our study.
Subgroup Analysis According to Risk Factors
Multivariate analysis showed that CVD history also had some influence on ECG changes (OR: 1.894; 95% CI: 0.986–3.638, P = 0.055). We performed subgroup analysis by dividing the patients into four groups according to the risk factors CVD and MHD: Higher-MHD Group (n = 109), Lower-MHD Group (n = 93), CVD Group (n = 58), and Non-CVD Group (n = 144). As shown in Fig. 3, the risk of ECG changes appeared to be increased for the patients with a CVD history in the Higher-MHD Group compared with patients without a CVD history, but the difference was not statistically significant. In the Lower-MHD Group, similar rates of ECG changes were observed in patients with or without CVD history. In addition, compared with patients who received lower-dose radiation, patients who were exposed to higher-dose radiation were at greater risk for ECG changes, whether in the CVD Group or Non-CVD Group (P < 0.05). Subgroup analysis further showed that a higher MHD was a significant risk factor for ECG changes.
FIG. 3
Proportion of patients with ECG changes after irradiation in different subgroups. Panel A: Higher-MHD group. Panel B: Lower-MHD group. Panel C: CVD group. Panel D: Non-CVD group. The height of the bar represents the proportion of patients with ECG changes. *P < 0.05 Higher-MHD group vs. Lower-MHD group; ns, P > 0.05 CVD group vs. non-CVD group.
Changes in Biomarker Levels from Pre-Treatment to Post-Treatment
Finally, we explored the associations between biomarker changes after irradiation and ECG changes. Among 202 patients, hs-cTnT was measured in 84 patients and NT-proBNP was measured in 64 patients before and after irradiation. The proportions of patients who experienced >30% increases in hs-cTnT and NT-proBNP compared to the respective baseline levels were 48.8% and 60.94%, respectively. The changes in biomarker levels from pretreatment to post-treatment are presented in Fig. 4. The analysis showed that hs-cTnT and NT-proBNP were significantly higher after irradiation than before irradiation (P < 0.01). The results in Fig. 5 show a statistically significant correlation between ECG changes and biomarker changes. The percentage of patients with ECG changes among patients with elevated biomarker levels was significantly higher than that among patients without elevated biomarker levels (P < 0.05). As shown in Fig. 6, the median time at which elevated biomarker levels were detected was shorter than the median time to the detection of ECG changes (2 months vs. 3 months).
FIG. 4
Changes in biomarker levels from pre-treatment (pre-RT) to post-treatment (post-RT). Box plots depict biomarker distributions from pre-RT to post-RT. Hs-cTnT: High-sensitivity cardiac troponin T; NT-proBNP: N-terminal B-type natriuretic peptide. Hs-cTnT concentrations <3 pg/ml were considered as 3 pg/ml for analysis. **P < 0.01 Pre-RT vs. Post-RT.
FIG. 5
Proportion of patients with ECG changes according to elevation of different biomarkers. Panel A: Hs-cTnT. Panel B: NT-proBNP. The height of the bars represents the proportion of patients with ECG changes. Biomarkers levels increased by at least 30% compared with baseline were considered elevated. *P < 0.05 Elevation group vs. non-elevation group.
DISCUSSION
In this retrospective study, we evaluated early ECG changes and risk factors for cardiovascular toxicity in patients who received thoracic radiation therapy, and our main findings are as follows. First, ECG changes occurred in 46.5% of patients, at a median time of 3 months postirradiation. Second, a higher MHD and elevated biomarker levels were significant risk factors associated with ECG changes. Third, hs-cTnT and NT-proBNP levels increased significantly at the median time of 2 months postirradiation compared to pre-treatment levels, and these increases in biomarker levels occurred earlier than the observed ECG changes.
In this study, we found that exposure to radiation led to ECG changes in almost half of the patients at a median of 3 months postirradiation. The most common alterations on ECG were arrhythmias, T-wave changes, ST changes, and poor R-wave progression. Arrhythmias can develop in patients after irradiation as a result of radiation-induced heart damage with involvement of the conduction system (27). Conduction system injury can be related to direct irradiation or secondary to myocardial inflammation, ischemia, or fibrosis (28). Bradycardia was the most common arrhythmia in our study, but typically asymptomatic. A few patients developed atrioventricular block and left/right bundle branch block after irradiation. In these patients with bradycardia or conduction block, chemotherapeutics associated with bradycardia, such as crizotinib and paclitaxel, should be used very carefully, with proper monitoring of heart rate and blood pressure (27). Tachycardia was common in our study population, and some patients with tachycardia developed symptoms of palpitations after RT. Sinus tachycardia has been recognized as a sign of extensive RIHD and can result in reduced exercise capacity and potentially increase the risk of tachycardia-mediated cardiomyopathy (29). Therefore, clinicians should actively search for the causes of tachycardia in patients receiving radiation therapy to avoid an adverse clinical prognosis due to potential cardiac toxicity related to tumor treatment. Cancer patients themselves are at high risk of atrial fibrillation, and anti-tumor therapy, including radiation therapy, may increase the risk of atrial fibrillation in cancer patients (27). In our study, two patients with preexisting arrhythmia developed atrial fibrillation with palpitations and chest tightness after receiving higher dose irradiation (MHD: 10.0–20.0 Gy). Early identification and timely intervention might improve the prognosis patients with atrial fibrillation. In addition, T-wave changes and ST changes were also prevalent in our study. ST-T wave changes are generally considered reflective of myocardial or pericardial injury (30). Pericarditis and myocardial ischemia related to radiation treatment may be possible explanations for the ST-T wave changes observed in our patients. Poor R-wave progression may also be associated with myocardial ischemia and dysfunction caused by radiation (31).
Previous studies have also evaluated the effect of radiation on ECG parameters. One study found that up to 50% of patients receiving mediastinal irradiation showed ECG changes, which usually occurred in the first year following treatment, were transient and did not cause symptoms (32). Strender et al. described early ECG abnormalities and found that 45% of 197 breast cancer patients had abnormal ECG findings at 6 months postirradiation, with a high incidence of T-wave changes among the left-sided patients (33). Furthermore, in a limited-sized prospective study among 25 patients receiving a high cardiac dose of radiation, Gomez et al. observed that nearly half of the patients had ECG changes by the end of treatment or 1–2 months after treatment, with septal T-wave changes and poor R-wave progression as the most common abnormalities (19). In another study including only locally-advanced non-small cell lung cancer patients treated with a median of 64 Gy in 1.8–2.0-Gy fractions using IMRT plus chemotherapy, Hotca et al. observed that arrhythmia was most common (53%), followed by ischemic/pericardial ECG abnormalities (35%), and non-specific abnormalities were more prevalent than arrhythmic and ischemic/pericardial abnormalities during the follow-up period (20). In our study, about 1/3 of patients experienced a return of ECG parameters to baseline levels in the follow-up period, and most of these patients had no pre-existing CVD (77.4%). However, for nearly 2/3 of cases, the ECG parameters did not return to baseline levels, and only 61.9% of these patients had no pre-existing CVD. ECG results appeared to recover more easily in patients without a history of CVD. In addition, we found that the proportion of patients who received higher MHD among the patients without ECG recovery was higher than that among patients with ECG recovery (68.3% vs. 58.1%). A previous study demonstrated a significant association between ECG abnormalities and OS, with higher doses leading to ECG abnormalities and shorter survival times (20). Another study confirmed the association between higher all-cause death rate and ECG changes at 6 months postirradiation, which tentatively suggested a link between all-cause death rate and radiation-induced cardiac damage (26). Close monitoring and long-term follow-up may be needed for patients without ECG recovery to prevent more serious cardiac events.
Multiple risk factors may affect the cardiotoxicity associated with radiation. Our study showed that MHD was a significant factor associated with ECG changes. Previous studies reported the dose-effect relationship of cardiotoxicity (2, 4, 34). Consistent with previous studies, our study provides evidence of the significant effect of a higher MHD on cardiotoxicity. The median MHD was higher in patients with ECG changes (7.6 Gy) compared with patients without ECG changes (4.3 Gy). Therefore, strict control of cardiac radiation dose may lead to lower rates of cardiac event. In addition, some studies have analyzed the effect of tumor location on the occurrence of cardiac events (35, 36). A study based on tumor laterality analysis found no significant difference in the incidence of cardiac events between right and left breast cancer patients (35), which may be due to the wide variability of MHD. Although the median MHD was higher in patients with left-sided tumors than in those with right-sided tumors, the MHD distribution varied considerably. Tumor location was not considered in our study.
The effect of radiation on the heart is magnified by cardiac risk factors such as hypertension, diabetes, smoking, obesity, and prior history of heart disease (2). A similar pattern was also found in the study of Hotca et al., in which the incidence of ECG abnormalities was associated with heart disease, hypertension, and diabetes (20). In our study, 32 (34.0%) of 94 patients with ECG changes had preexisting CVD including hypertension, diabetes, and heart disease. Among 108 patients without ECG changes, only 26 (24.1%) had pre-existing CVD. In the subgroup analysis, patients who received a higher MHD were at a higher risk for ECG changes compared with patients who received a lower MHD regardless of CVD history, which indicates that measures to minimize cardiac radiation dose should be routinely implemented, even in patients without any CVD. In addition, we found that the percentage of patients with CVD who exhibited ECG changes after receiving higher MHD tended to be higher than that among patients without CVD. This trend suggests that a history of CVD might be an adverse factor for patients with higher-dose cardiac exposure, and further research is needed to confirm this possibility. Accordingly, clinicians should take full account of cardiac dose as well as tumor control when formulating the radiation therapy plan for this patient population.
Multivariate analyses showed that elevation of biomarker levels also corresponded with an increased risk of ECG changes. Hs-cTnT and NT-proBNP have been identified as useful for the early detection of myocardial dysfunction and heart failure related to cancer therapies (9, 37). Hs-cTnT was increased at the median time of 2 months postirradiation in our study. Even a very small elevation of hs-cTnT has important prognostic significance. Single-center studies showed that a new increase in cardiac troponin I from the normal baseline may identify patients with cardiac dysfunction and poor prognosis, particularly when troponin elevation persists (38, 39). Elevation of NT-pro BNP was also observed after irradiation. The value of BNP in detecting heart failure has been widely confirmed, and an increase in BNP may represent direct myocardial injury and potential diastolic dysfunction (40). A small increase in troponin and any increase in BNP may predict worse prognosis among patients with heart failure (41). Some previous studies showed that levels of cardiac troponins and natriuretic peptides were not significantly affected by thoracic radiation therapy (19, 24, 25). Biomarkers were detected at specific time points after irradiation in these studies. However, biomarkers were dynamically detected in our study, which may better reflect the change rule for biomarkers after irradiation. In this study, significant associations were observed between ECG changes and elevation of hs-cTnT and NT-pro BNP after irradiation. The patients with elevated biomarker levels were at greater risk for ECG changes. In addition, we found that elevation of biomarker levels occurred earlier than ECG changes in this study, indicating that increased biomarker levels may allow early identification of patients with a higher risk of cardiotoxicity. Moreover, the combination of MHD and biomarkers may better identify high-risk patients and guide therapy. In addition to the factors included in this study, patient characteristics such as hyperlipidemia, tumor volume, performance status, and nodal stage also may affect cardiotoxicity in patients treated with thoracic radiation therapy (42, 43). Further research including all these factors is warranted.
Our study has a number of limitations. First, we included all patients regardless of chemotherapy or other treatment history to enhance the generalizability of our findings. Nonetheless, univariate analysis indicated that chemotherapy had no significant effect on ECG changes in our study. Other studies have also shown that radiation-induced cardiotoxicity occurs independently of chemotherapy and other treatment regimens (4, 22). Second, we included patients with multiple tumor types, most notably lung cancer, as we are unaware of any studies indicating that tumor type can affect cardiac toxicity. Third, the study was relatively small, especially in relation to biomarker measurement, limiting the statistical power of the study and our ability to adequately interpret the results. In fact, our goal was not to provide definitive conclusions about the effects of thoracic radiation therapy on cardiotoxicity but rather to observe whether short-term trends could be observed in acute cases. Finally, the follow-up time was relatively short; however, our focus was to evaluate the acute cardiotoxicity associated with thoracic radiation therapy based on ECG changes. A longer follow-up may be needed to elucidate the relationship between these changes and the risk of heart disease in patients treated with thoracic radiation therapy. We are continuing to follow these patients to observe whether further cardiotoxicity occurs.
CONCLUSIONS
In conclusion, this study indicates that nearly half of patients experienced ECG changes after thoracic radiation therapy, and a higher MHD and elevated hs-cTnT and NT-pro BNP level were important risk factors for ECG changes. It is necessary to strengthen cardiovascular monitoring and/or cardioprotective therapy for patients with these risk factors. These findings emphasize that the risk of radiation-related cardiotoxicity should not be overlooked, and combining ECG with biomarkers and advanced imaging techniques may provide more insight into radiation-induced cardiotoxicity.
©2023 by Radiation Research Society.
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REFERENCES
Notes
[1] 2 Editor's note. The online version of this article (DOI: https://doi.org/10.1667/RADE-22-00134.1) contains supplementary information that is available to all authorized users.
