Radiation-induced heart disease: a review of classification, mechanism and prevention

The Evaluation and Management of Visceral Complications in Radiation Fibrosis Syndrome Part 1

Abstract

External beam ionizing radiation is a fundamental component of cancer treatment and is incorporated into approximately 50% of cancer treatments. Radiation therapy causes cell death directly by apoptosis and indirectly by disruption of mitosis.

Purpose of Review

This study aims to inform rehabilitation clinicians of the visceral toxicities of radiation fibrosis syndrome and how to detect and diagnose these complications.

Recent Findings

Latest research indicates that radiation toxicity is primarily related to radiation dose, patient co-morbidity, and concomitant use of chemotherapies and immunotherapies for the treatment of cancer. While cancer cells are the primary target, surrounding normal cells and tissues are also affected. Radiation toxicity is dose dependent, and tissue injury develops from inflammation that may progress to fibrosis. Thus, radiation dosing in cancer therapy is often limited by tissue toxicity. Although newer radiotherapeutic modalities aim to limit delivery of radiation to non-cancerous tissues, many patients continue to experience toxicity.

Summary

To ensure early recognition of radiation toxicity and fibrosis, it is imperative that all clinicians are aware of the predictors, signs, and symptoms of radiation fibrosis syndrome. Here, we present part 1 of the visceral complications of radiation fibrosis syndrome, addressing radiation-related toxicity in the heart, lungs, and thyroid gland.

Graphical abstract

Radiation Treatment Mechanisms of Cardiotoxicity: A Systematic Review

Radiotherapy may be used alone or in combination with chemotherapy for cancer treatment. There are many mechanisms of radiation treatment exposure to toxicities. Our aim was to summarize the literature about known mechanisms of radiation-induced cardiac toxicities. We performed a systematic review of the literature on the PubMed database until October 2022 about cardiovascular toxicities and radiation therapy exposure. Only systematic reviews, meta-analyses, and reviews were selected. Out of 1429 publications screened, 43 papers met inclusion criteria and were selected for the umbrella review process. Microvascular and macrovascular complications could lead to adverse cardiac effects. Many radiotherapy-associated risk factors were responsible, such as the site of radiation treatment, beam proximity to heart tissues, total dosage, the number of radiotherapy sessions, adjuvant chemotherapeutic agents used, and patient traditional cardiovascular risk factors, patient age, and gender. Moreover, important dosage cutoff values could increase the incidence of cardiac toxicities. Finally, the time from radiation exposure to cardiac side effects was assessed. Our report highlighted mechanisms, radiation dosage values, and the timeline of cardiovascular toxicities after radiation therapy. All of the above may be used for the assessment of cardiovascular risk factors and the development of screening programs for cancer patients.

Lifetime Evaluation of Left Ventricular Structure and Function in Male C57BL/6J Mice after Gamma and Space-Type Radiation Exposure

The lifetime effects of space irradiation (IR) on left ventricular (LV) function are unknown. The cardiac effects induced by space-type IR, specifically 5-ion simplified galactic cosmic ray simulation (simGCRsim), are yet to be discovered. Three-month-old, age-matched, male C57BL/6J mice were irradiated with 137Cs gamma (γ; 100, 200 cGy) and simGCRsim (50 and 100 cGy). LV function was assessed via transthoracic echocardiography at 14 and 28 days (early), and at 365, 440, and 660 (late) days post IR. We measured the endothelial function marker brain natriuretic peptide in plasma at three late timepoints. We assessed the mRNA expression of the genes involved in cardiac remodeling, fibrosis, inflammation, and calcium handling in LVs harvested at 660 days post IR. All IR groups had impaired global LV systolic function at 14, 28, and 365 days. At 660 days, 50 cGy simGCRsim-IR mice exhibited preserved LV systolic function with altered LV size and mass. At this timepoint, the simGCRsim-IR mice had elevated levels of cardiac fibrosis, inflammation, and hypertrophy markers Tgfβ1, Mcp1, Mmp9, and βmhc, suggesting that space-type IR may induce the cardiac remodeling processes that are commonly associated with diastolic dysfunction. IR groups showing statistical significance were modeled to calculate the Relative Biological Effectiveness (RBE) and Radiation Effects Ratio (RER). The observed dose-response shape did not indicate a lower threshold at these IR doses. A single full-body IR at doses of 100-200 cGy for γ-IR, and 50-100 cGy for simGCRsim-IR decreases the global LV systolic function in WT mice as early as 14 and 28 days after exposure, and at 660 days post IR. Interestingly, there is an intermediate time point (365 days) where the impairment in LV function is observed. These findings do not exclude the possibility of increased acute or degenerative cardiovascular disease risks at lower doses of space-type IR, and/or when combined with other space travel-associated stressors such as microgravity.

New Insights into the Role of Ferroptosis in Cardiovascular Diseases

Cardiovascular diseases (CVDs) are the principal cause of disease burden and death worldwide. Ferroptosis is a new form of regulated cell death mainly characterized by altered iron metabolism, increased polyunsaturated fatty acid peroxidation by reactive oxygen species, depletion of glutathione and inactivation of glutathione peroxidase 4. Recently, a series of studies have indicated that ferroptosis is involved in the death of cardiac and vascular cells and has a key impact on the mechanisms leading to CVDs such as ischemic heart disease, ischemia/reperfusion injury, cardiomyopathies, and heart failure. In this article, we reviewed the molecular mechanism of ferroptosis and the current understanding of the pathophysiological role of ferroptosis in ischemic heart disease and in some cardiomyopathies. Moreover, the comprehension of the machinery governing ferroptosis in vascular cells and cardiomyocytes may provide new insights into preventive and therapeutic strategies in CVDs.

Recent Advances in Serum Biomarkers for Risk Stratification and Patient Management in Cardio-Oncology

PURPOSE OF REVIEW

Following significant advancements in cancer therapeutics and survival, the risk of cancer therapy-related cardiotoxicity (CTRC) is increasingly recognized. With ongoing efforts to reduce cardiovascular morbidity and mortality in cancer patients and survivors, cardiac biomarkers have been studied for both risk stratification and monitoring during and after therapy to detect subclinical disease. This article will review the utility for biomarker use throughout the cancer care continuum.

RECENT FINDINGS

A recent meta-analysis shows utility for troponin in monitoring patients at risk for CTRC during cancer therapy. The role for natriuretic peptides is less clear but may be useful in patients receiving proteasome inhibitors. Early studies explore use of myeloperoxidase, growth differentiation factor 15, galectin 3, micro-RNA, and others as novel biomarkers in CTRC. Biomarkers have potential to identify subclinical CTRC and may reveal opportunities for early intervention. Further research is needed to elucidate optimal biomarkers and surveillance strategies.

Dang Gui Bu Xue Tang, a conventional Chinese herb decoction, ameliorates radiation-induced heart disease via Nrf2/HMGB1 pathway

Introduction: Radiation-induced heart disease (RIHD), characterized by cardiac dysfunction and myocardial fibrosis, is one of the most common complications after cardiothoracic radiotherapy. Dang Gui Bu Xue Tang (DBT) is a conventional Chinese herb decoction composed of Radix Astragali membranaceus (RAM) and Radix Angelicae sinensis (RAS) at a ratio of 5:1, famous for its "blood-nourishing" effect. In this study, we aimed to investigate the cardioprotective effect of DBT on RIHD. Methods: C57BL mice at 8 weeks of age were divided into five groups, namely Control, Radiation, RDBT51 (Radiation with DBT, RAM:RAS = 5:1), RDBT11 (Radiation with DBT, RAM:RAS = 1:1), and RDBT15 (Radiation with DBT, RAM:RAS = 1:5). Results: We mainly found that radiation in the cardiothoracic region led to significant left ventricular systolic dysfunction, myocardial fibrotic lesions and cardiac injury accompanied by abnormally increased myocardial HMGB1 protein levels. Administration of conventional DBT significantly ameliorated left ventricular systolic dysfunction, alleviated myocardial fibrosis, and counteracted cardiac injury, all of which supported the protective effect of DBT on RIHD, involving upregulation of myocardial Nrf2 protein levels and downregulation of HMGB1 protein levels as underlying mechanisms. Conclusions: DBT exerts a significant protective effect on RIHD, and the Nrf2/ HMGB1 pathway probably plays an important role in this protective effect.

New Insights into the Understanding of Mechanisms of Radiation-Induced Heart Disease

OPINION STATEMENT

Cancer patients who receive high-dose thoracic radiotherapy may develop radiation-induced heart disease (RIHD). The clinical presentation of RIHD comprises coronary artery atherosclerosis, valvular disease, pericarditis, cardiomyopathy, and conduction defects. These complications have significantly reduced due to the improved radiotherapy techniques. However, such methods still could not avoid heart radiation exposure. Furthermore, people who received relatively low-dose radiation exposures have exhibited significantly elevated RIHD risks in cohort studies of atomic bomb survivors and occupational exposures. The increased potential in exposure to natural and artificial ionizing radiation sources has emphasized the necessity to understand the development of RIHD. The pathological processes of RIHD include endothelial dysfunction, inflammation, fibrosis, and hypertrophy. The underlying mechanisms may involve the changes in oxidative stress, DNA damage response, telomere erosion, mitochondrial dysfunction, epigenetic regulation, circulation factors, protein post-translational modification, and metabolites. This review will discuss the recent advances in the mechanisms of RIHD at cellular and molecular levels.

Clinical and Dosimetric Predictors for Postoperative Cardiopulmonary Complications in Esophageal Squamous Cell Carcinoma Patients Receiving Neoadjuvant Chemoradiotherapy and Surgery

BACKGROUND

Neoadjuvant chemoradiotherapy followed by esophagectomy is the standard treatment for patients with locally advanced esophageal squamous cell carcinoma (ESCC). This study explored correlations of clinical factors and dose-volume histogram (DVH) parameters with postoperative cardiopulmonary complications and predicted their risk by establishing a nomogram model.

METHODS

Clinical and DVH parameters of ESCC patients who underwent trimodality treatment from 2002 to 2020 were collected. Postoperative cardiopulmonary complications were recorded. Logistic regression analysis was applied, and a nomogram model was constructed. Area under the receiver operating characteristic (AUC) curve, calibration curve, and decision curve analyses were performed to evaluate the performance of the nomogram.

RESULTS

Of the 307 ESCC patients enrolled in this study, 65 (21.2%) experienced pulmonary complications and 57 (18.6%) experienced cardiac complications. The following six risk factors were identified as independent risk factors for pulmonary complications by multivariate logistic regression analyses in the integrated model: male sex (odds ratio [OR], 3.26; 95% confidence interval [CI], 1.27-9.70; P = 0.021), post-radiation therapy (RT) forced expiratory volume in 1 s (FEV1) (OR, 0.51; 95% CI 0.28-0.90; P = 0.023), mean lung dose (MLD) (OR, 1.13; 95% CI 1.01-1.28; P = 0.041), and pre-RT monocyte (OR, 8.36; 95% CI 1.23-11.7; P = 0.03). The AUC of this integrated model was 0.705 (95% CI 0.64-0.77). The paclitaxel and cisplatin (TP) concurrent chemotherapy regimen was the independent predictor of cardiac complication (OR, 2.50; 95% CI 1.22-5.55; P = 0.016).

CONCLUSIONS

For ESCC patients who underwent trimodality treatment, male sex, post-RT FEV1, MLD, and pre-RT monocyte were confirmed as significant predictors of postoperative pulmonary complications. A nomogram model including six risk factors was further established. The independent predictor of cardiac complication was TP concurrent chemotherapy.

Case report: Early acute myocarditis after radiation therapy for breast cancer: A case presentation and review of literature

Breast cancer is the most commonly diagnosed cancer in women worldwide, and with the increased survival of patients by novel treatments, the frequency of complications of cancer treatments rises. Radiotherapy, especially on the chest wall, can damage different cardiac structures. Radiotherapy-induced cardiomyopathy mainly occurs over 10 years after breast cancer treatment; however, there is a gap in the literature on acute myocarditis following radiotherapy. Here, we present a 54-year-old woman who developed acute myocarditis shortly after 25 sessions of radiotherapy with 50 Gy of radiation, successfully diagnosed with the use of speckle tracking echocardiography (STE) and cardiac magnetic resonance (CMR), and responded to the medical treatment with relative clinical improvement until the final follow-up. This case suggests the necessity of detailed examination of patients after radiotherapy, not only for chronic occurrence of cardiomyopathy but also for acute myocarditis. Although STE and CMR resulted in accurate diagnosis, in this case, further studies are required to determine the diagnostic accuracy of these two imaging methods compared with other imaging modalities in such patients and investigate the best diagnostic tool and therapeutic approach for these patients.

Modulators of radiation-induced cardiopulmonary toxicities for non-small cell lung cancer: Integrated cytokines, single nucleotide variants, and HBP systems imaging

Radiation therapy (RT)-induced cardiopulmonary toxicities remain dose-limiting toxicities for patients receiving radiation dosages to the thorax, especially for lung cancer. Means of monitoring and predicting for those receiving RT or concurrent chemoradiation therapy before treatment begins in individual patients could benefit early intervention to prevent or minimize RT-induced side effects. Another aspect of an individual's susceptibility to the adverse effects of thoracic irradiation is the immune system as reflected by phenotypic factors (patterns of cytokine expressions), genotypic factors (single nucleotide variants SNVs; formerly single nucleotide polymorphisms [SNPs]), and aspects of quantitative cellular imaging. Levels of transcription, production, and functional activity of cytokines are often influenced by SNVs that affect coding regions in the promoter or regulatory regions of cytokine genes. SNVs can also lead to changes in the expression of the inflammatory cytokines, interferons, interleukins (IL-6, IL-17) and tumor necrosis factors (TNF-α) at the protein level. RT-induced cardiopulmonary toxicities could be quantified by the uptake of ¹⁸F-fluorodeoxyglucose (FDG), however, FDG is a sensitive but not specific biomarker in differential diagnosis between inflammation/infection and tumor recurrence. FDG is suitable for initial diagnosis of predisposed tissue injuries in non-small cell lung cancer (NSCLC). ^99mTc-ethylenedicysteine-glucosamine (^99mTc-EC-G) was able to measure tumor DNA proliferation and myocardial ischemia via hexosamine biosynthetic pathways (HBP). Thus, ^99mTc-EC-G could be an alternative to FDG in the assessment of RT doses and select patients in HBP-directed targets for optimal outcomes. This article reviewed correlative analyses of pro-inflammatory cytokines, genotype SNVs, and cellular imaging to improve the diagnosis, prognosis, monitoring, and prediction of RT-induced cardiopulmonary toxicities in NSCLC.

Cardiac Adverse Events Associated With Chemo-Radiation Versus Chemotherapy for Resectable Stage III Non-Small-Cell Lung Cancer: A Surveillance, Epidemiology and End Results-Medicare Study

Background We compared cardiac outcomes for surgery-eligible patients with stage III non-small-cell lung cancer treated adjuvantly or neoadjuvantly with chemotherapy versus chemo-radiation therapy in the Surveillance, Epidemiology and End Results-Medicare database. Methods and Results Patients were age 66+, had stage IIIA/B resectable non-small-cell lung cancer diagnosed between 2007 and 2015, and received adjuvant or neoadjuvant chemotherapy or chemo-radiation within 121 days of diagnosis. Patients having chemo-radiation and chemotherapy only were propensity-score matched and followed from day 121 to first cardiac outcome, noncardiac death, radiation initiation by patients who received chemotherapy only, fee-for-service enrollment interruption, or December 31, 2016. Cause-specific hazard ratios (HRs) and competing risks subdistribution HRs were estimated. The primary outcome was the first of these severe cardiac events: acute myocardial infarction, other hospitalized ischemic heart disease, hospitalized heart failure, percutaneous coronary intervention/coronary artery bypass graft, cardiac death, or urgent/inpatient care for pericardial disease, conduction abnormality, valve disorder, or ischemic heart disease. With median follow-up of 13 months, 70 of 682 patients who received chemo-radiation (10.26%) and 43 of 682 matched patients who received chemotherapy only (6.30%) developed a severe cardiac event (P=0.008) with median time to first event 5.45 months. Chemo-radiation increased the rate of severe cardiac events (cause-specific HR: 1.62 [95% CI, 1.11-2.37] and subdistribution HR: 1.41 [95% CI, 0.97-2.04]). Cancer severity appeared greater among patients who received chemo-radiation (noncardiac death cause-specific HR, 2.53 [95% CI, 1.93-3.33] and subdistribution HR, 2.52 [95% CI, 1.90-3.33]). Conclusions Adding radiation therapy to chemotherapy is associated with an increased risk of severe cardiac events among patients with resectable stage III non-small-cell lung cancer for whom survival benefit of radiation therapy is unclear.

[Radiation-Induced Heart Disease: Current Status and Challenges]

Being one of the major therapeutic measures for malignant tumors, radiation therapy, or radiotherapy, plays a particularly crucial role in the multidisciplinary integrated treatment of thoracic tumors. With the development in radiotherapy technology, the research focus has shifted from improving the overall survival of malignant tumor patients to reducing the incidence of radiation-related injuries. Currently, radiation-induced heart disease (RIHD) has become one of the leading non-cancer causes of death in thoracic tumor patients who have undergone radiotherapy, seriously affecting their quality of life and clinical prognosis. In recent years, there has been growing understanding of the pathogenesis of RIHD, and proposals have been made for some potential measures for the prevention and treatment of RIHD. Based on the clinical manifestations and pathological changes of RIHD that have been reported, we herein reviewed the biological mechanism and potential treatment options for RIHD. We also discussed existing challenges in the prevention and treatment of RIHD, intending to provide references for the prevention and treatment of RIHD.

Ionizing radiation, cerebrovascular disease, and consequent dementia: A review and proposed framework relevant to space radiation exposure

Space exploration requires the characterization and management or mitigation of a variety of human health risks. Exposure to space radiation is one of the main health concerns because it has the potential to increase the risk of cancer, cardiovascular disease, and both acute and late neurodegeneration. Space radiation-induced decrements to the vascular system may impact the risk for cerebrovascular disease and consequent dementia. These risks may be independent or synergistic with direct damage to central nervous system tissues. The purpose of this work is to review epidemiological and experimental data regarding the impact of low-to-moderate dose ionizing radiation on the central nervous system and the cerebrovascular system. A proposed framework outlines how space radiation-induced effects on the vasculature may increase risk for both cerebrovascular dysfunction and neural and cognitive adverse outcomes. The results of this work suggest that there are multiple processes by which ionizing radiation exposure may impact cerebrovascular function including increases in oxidative stress, neuroinflammation, endothelial cell dysfunction, arterial stiffening, atherosclerosis, and cerebral amyloid angiopathy. Cerebrovascular adverse outcomes may also promote neural and cognitive adverse outcomes. However, there are many gaps in both the human and preclinical evidence base regarding the long-term impact of ionizing radiation exposure on brain health due to heterogeneity in both exposures and outcomes. The unique composition of the space radiation environment makes the translation of the evidence base from terrestrial exposures to space exposures difficult. Additional investigation and understanding of the impact of low-to-moderate doses of ionizing radiation including high (H) atomic number (Z) and energy (E) (HZE) ions on the cerebrovascular system is needed. Furthermore, investigation of how decrements in vascular systems may contribute to development of neurodegenerative diseases in independent or synergistic pathways is important for protecting the long-term health of astronauts.

What Causes Death in Esophageal Cancer Patients Other Than the Cancer Itself: A Large Population-Based Analysis

Background: Researches on noncancer causes of death in patients with esophageal cancer (EC) are not in-depth. The objective of this paper is to broadly and deeply explore the causes of death in patients with EC, especially noncancer causes.

Methods: Information about the demographics, tumor-related characteristics, and causes of death of patients with EC who met the inclusion criteria were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Calculated standardized mortality ratio (SMR) for all causes of death at different follow-up times and performed subgroup analyses.

Results: In total, 63,560 patients with EC were retrieved from the public database. And 52,503 died during the follow-up period. Most deaths were due to EC itself within 5 years after diagnosis, but over 10 years, 59% EC patients died from noncancer causes. Cardiovascular disease was the major noncancer cause of death in patients with EC, accounting for 43%. Suicide and self-injury (2%) of EC patients should not be ignored. During the 1-year follow-up period, patients with EC had statistically highest risk of death from septicemia (SMR: 7.61; 95% CI: 6.38-9.00). Within more than 10 years after EC diagnosis, more and more patients died from chronic obstructive pulmonary disease (SMR: 2.38; 95% CI: 1.79-3.10).

Conclusions: Although most patients with EC still died from the cancer itself, the role of noncancer causes of death should not be underestimated. These prompt clinicians to pay more attention to the risk of death caused by these noncancer causes, which can provide relevant measures in advance to intervene.

Cardio-Oncology: Mechanisms, Drug Combinations, and Reverse Cardio-Oncology

Chemotherapy, radiotherapy, targeted therapy, and immunotherapy have brought hope to cancer patients. With the prolongation of survival of cancer patients and increased clinical experience, cancer-therapy-induced cardiovascular toxicity has attracted attention. The adverse effects of cancer therapy that can lead to life-threatening or induce long-term morbidity require rational approaches to prevention and treatment, which requires deeper understanding of the molecular biology underpinning the disease. In addition to the drugs used widely for cardio-protection, traditional Chinese medicine (TCM) formulations are also efficacious and can be expected to achieve “personalized treatment” from multiple perspectives. Moreover, the increased prevalence of cancer in patients with cardiovascular disease has spurred the development of “reverse cardio-oncology”, which underscores the urgency of collaboration between cardiologists and oncologists. This review summarizes the mechanisms by which cancer therapy induces cardiovascular toxicity, the combination of antineoplastic and cardioprotective drugs, and recent advances in reverse cardio-oncology.

Radiotherapy combined with immunotherapy: the dawn of cancer treatment

Radiotherapy (RT) is delivered for purposes of local control, but can also exert systemic effect on remote and non-irradiated tumor deposits, which is called abscopal effect. The view of RT as a simple local treatment has dramatically changed in recent years, and it is now widely accepted that RT can provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). Nevertheless, several points remain to be addressed such as the interaction of RT and immune system, the identification of the best schedules for combination with immunotherapy (IO), the expansion of abscopal effect and the mechanism to amplify iRT. To answer these crucial questions, we roundly summarize underlying rationale showing the whole immune landscape in RT and clinical trials to attempt to identify the best schedules of iRT. In consideration of the rarity of abscopal effect, we propose that the occurrence of abscopal effect induced by radiation can be promoted to 100% in view of molecular and genetic level. Furthermore, the “radscopal effect” which refers to using low-dose radiation to reprogram the tumor microenvironment may amplify the occurrence of abscopal effect and overcome the resistance of iRT. Taken together, RT could be regarded as a trigger of systemic antitumor immune response, and with the help of IO can be used as a radical and systemic treatment and be added into current standard regimen of patients with metastatic cancer.

Cardiac Remodelling Following Cancer Therapy: A Review

Cardiac remodelling is characterized by abnormal changes in the function and morphological properties such as diameter, mass, normal diameter of cavities, heart shape, fibrosis, thickening of vessels and heart layers, cardiomyopathy, infiltration of inflammatory cells, and some others. These damages are associated with damage to systolic and diastolic abnormalities, damage to ventricular function, and vascular remodelling, which may lead to heart failure and death. Exposure of the heart to radiation or anti-cancer drugs including chemotherapy drugs such as doxorubicin, receptor tyrosine kinase inhibitors (RTKIs) such as imatinib, and immune checkpoint inhibitors (ICIs) can induce several abnormal changes in the heart structure and function through the induction of inflammation and fibrosis, vascular remodelling, hypertrophy, and some others. This review aims to explain the basic mechanisms behind cardiac remodelling following cancer therapy by different anti-cancer modalities.

MiRNA-Mediated Fibrosis in the Out-of-Target Heart following Partial-Body Irradiation

Recent reports have shown a link between radiation exposure and non-cancer diseases such as radiation-induced heart disease (RIHD). Radiation exposures are often inhomogeneous, and out-of-target effects have been studied in terms of cancer risk, but very few studies have been carried out for non-cancer diseases. Here, the role of miRNAs in the pathogenesis of RIHD was investigated. C57Bl/6J female mice were whole- (WBI) or partial-body-irradiated (PBI) with 2 Gy of X-rays or sham-irradiated (SI). In PBI exposure, the lower third of the mouse body was irradiated, while the upper two-thirds were shielded. From all groups, hearts were collected 15 days or 6 months post-irradiation. The MiRNome analysis at 15 days post-irradiation showed that miRNAs, belonging to the myomiR family, were highly differentially expressed in WBI and PBI mouse hearts compared with SI hearts. Raman spectral data collected 15 days and 6 months post-irradiation showed biochemical differences among SI, WBI and PBI mouse hearts. Fibrosis in WBI and PBI mouse hearts, indicated by the increased deposition of collagen and the overexpression of genes involved in myofibroblast activation, was found 6 months post-irradiation. Using an in vitro co-culture system, involving directly irradiated skeletal muscle and unirradiated ventricular cardiac human cells, we propose the role of miR-1/133a as mediators of the abscopal response, suggesting that miRNA-based strategies could be relevant for limiting tissue-dependent reactions in non-directly irradiated tissues.

Myocardial Ischemia Related to Common Cancer Therapy-Prevention Insights

Modern antineoplastic therapy improves survival and quality of life in cancer patients, but its indisputable benefits are accompanied by multiple and major side effects, such as cardiovascular ones. Endothelial dysfunction, arterial spasm, intravascular thrombosis, and accelerated atherosclerosis affect the coronary arteries, leading to acute and chronic coronary syndromes that negatively interfere with the oncologic treatment. The cardiac toxicity of antineoplastic agents may be mitigated by using adequate prophylactic measures. In the absence of dedicated guidelines, our work provides the most comprehensive, systematized, structured, and up-to-date analyses of the available literature focusing on measures aiming to protect the coronary arteries from the toxicity of cancer therapy. Our work facilitates the implementation of these measures in daily practice. The ultimate goal is to offer clinicians the necessary data for a personalized therapeutic approach for cancer patients receiving evidence-based oncology treatments with potential cardiovascular toxicity.

Exercise echocardiography for a differential diagnosis in a patient with radiation-induced heart disease: A case report

Advances in radiation therapy (RT) have dramatically improved the survival rates of patients with cancer, but radiation-induced heart disease (RIHD) has become an emerging problem, which is complex and multifaceted.

A 65-year-old man with a medical history of chemoradiotherapy for esophageal cancer, who had multiple admissions for acute heart failure (AHF), was readmitted to our hospital. Transthoracic echocardiography at rest revealed left ventricular diastolic dysfunction, moderate aortic stenosis with mild aortic regurgitation, and mild mitral regurgitation (MR). A diagnosis of RIHD was obtained, however, the main cause of the AHF was not clearly understood. Exercise echocardiography (ExE) revealed an exacerbation of the MR and exercise-induced pulmonary hypertension (EIPH), and the severe dynamic MR was considered to be the main cause of the AHF. A transcatheter edge-to-edge repair (TEER) with a MitraClip (Abbott Vascular, Menlo Park, CA, USA) was performed, and the post-procedural ExE showed the mitigation of the dynamic MR and EIPH. He had no further heart failure admissions for more than one year.

Our case showed that ExE may be useful in the management of patients with RIHD, and a TEER with a MitraClip may be an effective treatment for RT-related dynamic MR.

Learning objective

Radiation therapy (RT) has improved the survival rates of patients with cancer, but which involves radiation-induced heart disease (RIHD). RIHD is complex and multifaceted, and RT-related valvular disease may be underestimated with transthoracic echocardiography at rest alone. Then exercise echocardiography may be useful in the management. It is important to perform an individualized approach including medical therapy, surgery, and percutaneous intervention by a heart team.

Breast cancer radiotherapy and the risk of acute coronary events - insights from a process oriented model

BACKGROUND AND PURPOSE

Acute coronary events (ACEs) are considered the most important side effect of radiotherapy (RT) for breast cancer but underlying mechanisms still have to be identified. Process oriented models mathematically describe the development of disease and provide a link between mechanisms and subsequent risk. Here, this link is exploited to learn about the underlying mechanisms from the observed age-time patterns of ACE risk.

MATERIALS AND METHODS

A process oriented model of atherosclerosis and subsequent ACEs was applied to a contemporary breast cancer cohort of 810 patients with measurements of coronary artery calcification. Patients with prior ischemic heart disease were excluded. The process oriented model describes disease development as a series of different stages. Different variants of the model were fitted to the data. In each variant, one stage was assumed to be accelerated in relation to mean heart dose.

RESULTS

During a mean follow up of 9.1 years, 25 ACEs occurred. The model reproduced the prevalence and associated risk of coronary calcifications. Mean heart dose significantly improved the fit only when implemented as affecting a late stage of atherosclerosis on already existing, complicated lesions (achieving p = 0.007). This can be understood by atherosclerosis being a slowly progressing disease. Therefore, an increase of ACEs few years after RT requires advanced atherosclerosis at the time of RT.

CONCLUSION

Risk of ACE increases within few years in patients with advanced atherosclerosis at RT. Therefore, patients should be assessed for cardiovascular risk, and also elderly patients need to be considered for heart sparing techniques.

Radiation-Induced Cardiac Dysfunction: Optimizing Radiation Delivery and Postradiation Care

Radiation therapy (RT) is part of standard-of-care treatment of many thoracic cancers. More than 60% of patients receiving thoracic RT may eventually develop radiation-induced cardiac dysfunction (RICD) secondary to collateral heart dose. This article reviews factors contributing to a thoracic cancer patient's risk for RICD, including RT dose to the heart and/or cardiac substructures, other anticancer treatments, and a patient's cardiometabolic health. It is also discussed how automated tracking of these factors within electronic medical record environments may aid radiation oncologists and other treating physicians in their ability to prevent, detect, and/or treat RICD in this expanding patient population.

Ferroptosis and its role in cardiomyopathy

Heart disease is the leading cause of death worldwide. Cardiomyopathy is a disease characterized by the heart muscle damage, resulting heart in a structurally and functionally change, as well as heart failure and sudden cardiac death. The key pathogenic factor of cardiomyopathy is the loss of cardiomyocytes, but the related molecular mechanisms remain unclear. Ferroptosis is a newly discovered regulated form of cell death, characterized by iron accumulation and lipid peroxidation during cell death. Recent studies have shown that ferroptosis plays an important regulatory roles in the occurrence and development of many heart diseases such as myocardial ischemia/reperfusion injury, cardiomyopathy and heart failure. However, the systemic association of ferroptosis and cardiomyopathy remains largely unknown and needs to be elucidated. In this review, we provide an overview of the molecular mechanisms of ferroptosis and its role in individual cardiomyopathies, highlight that targeting ferroptosis maybe a potential therapeutic strategy for cardiomyopathy therapy in the future.

Effectiveness of Proanthocyanidin plus Trimetazidine in the Treatment of Non-Small-Cell Lung Cancer with Radiation Heart Injury

This study was intended to explore the effect of proanthocyanidin (PC) combined with trimetazidine in non-small-cell lung cancer (NSCLC) with radiation-induced heart damage (RIHD). It was a prospective randomized controlled study that 86 NSCLC patients with radiation treatment in Cangzhou People's Hospital from January 2019 and June 2021 were enrolled and randomized to either the control group or the study group via the random table method, 43 cases in each group. The control group received trimetazidine, and the study group additionally received PC. The incidence of RIHD-related clinical manifestation, RIHD-related ECG, and RIHD-related cardiac ultrasound change were all lower in the study group. After radiotherapy, the serum level of superoxide dismutase (SOD) was higher, and malondialdehyde (MDA) was lower in the study group when compared with the control group. After radiotherapy, the serum levels of brain natriuretic peptide (BNP), cardiac troponin (cTnT), creatine kinase (CK), and creatine kinase isoenzymes (CKMB) were all lower in the study group when compared with the control group. The efficacy of PC plus trimetazidine for NSCLC with RIHD is superior to trimetazidine alone, and it significantly mitigates radiation-induced inflammatory response and oxidative stress.

Advanced Echocardiography Techniques: The Future Stethoscope of Systemic Diseases

Cardiovascular disease (CVD) has been showing patterns of extensive rise in prevalence in the contemporary era, affecting the quality of life of millions of people and leading the causes of death worldwide. It has been a provocative challenge for modern medicine to diagnose CVD in its crib, owing to its etiological factors being attributed to a large array of systemic diseases, as well as its non-binary hideous nature that gradually leads to functional disability. Novel echocardiography techniques have enabled the cardiac ultrasound to provide a comprehensive analysis of the heart in an objective, feasible, time- and cost-effective manner. Speckle tracking echocardiography, contrast echocardiography, and 3D echocardiography have shown the highest potential for widespread use. The uses of novel modalities have been elaborately demonstrated in this study as a proof of concept that echocardiography has a place in routine general practice with supportive evidence being as recent as its role in the concurrent COVID-19 pandemic. Despite such evidence, many uses remain off-label and unexploited in practice. Generalization of echocardiography at the point of care can become a much-needed turning point in the clinical approach to case management. To actualize such aspirations, we recommend further prospective and interventional studies to examine the effect of implementing advanced techniques at the point of care on the decision-making process and evaluate their effectiveness in prevention of cardiovascular morbidities and mortalities.

An overview of radiation-induced heart disease

Radiation therapy (RT) has dramatically improved cancer survival, leading to several inevitable complications. Unintentional irradiation of the heart can lead to radiation-induced heart disease (RIHD), including cardiomyopathy, pericarditis, coronary artery disease, valvular heart disease, and conduction system abnormalities. Furthermore, the development of RIHD is aggravated with the addition of chemotherapy. The screening, diagnosis, and follow-up for RIHD in patients who have undergone RT are described by the consensus guidelines from the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE). There is compelling evidence that chest RT can increase the risk of heart disease. Although the prevalence and severity of RIHD are likely to be reduced with modern RT techniques, the incidence of RIHD is expected to rise in cancer survivors who have been treated with old RT regimens. However, there remains a gap between guidelines and clinical practice. Currently, therapeutic modalities followed in the treatment of RIHD are similar to the non-irradiated population. Preventive measures mainly reduce the radiation dose and radiation volume of the heart. There is no concrete evidence to endorse the preventive role of statins, angiotensin-converting enzyme inhibitors, and antioxidants. This review summarizes the current evidence of RIHD subtypes and risk factors and suggests screening regimens, diagnosis, treatment, and preventive approaches.

The Influence of Radiotherapy on the Function of the Left and Right Ventricles in Relation to the Radiation Dose Administered to the Left Anterior Descending Coronary Artery—From a Cardiologist’s Point of View

The aim of this study was to assess the effects of radiotherapy involving the heart on LV and RV function using modern speckle-tracking echocardiography (STE), and in relation to the radiation dose applied to the LAD. This retrospective, single-centre study included 12 patients after a median of 51 months after irradiation for mediastinal lymphoma, in whom we were able to delineate the LAD. Correlations between doses of ionising radiation and echocardiographic parameters reflecting the systolic function of the LV and RV were analysed. The median irradiation dose delivered to the whole heart was 16.4 Gy (0.5–36.2 Gy), and to the LAD it was 15.1 Gy (0.3–35.3 Gy). LV longitudinal strain (LS) was impaired in the anteroseptal and anterior walls. Parameters reflecting RV function were normal, with the exception of RV myocardial performance index (RIMP). Significant correlations were found between the median dose to the LAD and LV global LS (rho = 0.6468, p = 0.034), the maximum dose to the LAD and LV anterior LS (rho = 0.6046, p = 0.049), the median and the mean dose to the whole heart and LV anterior LS (R = 0.772, p = 0.009 and rho = 0.7676, p = 0.01, respectively), and the total irradiation dose and RIMP (rho = 0.5981, p = 0.04). The calculation of irradiation doses allows the identification of patients at risk of cardiac dysfunction detected by modern STE.

Investigating Radioprotective Effect of Hesperidin/Diosmin Compound Against 99mTc-MIBI-Induced Cardiotoxicity: Animal Study

This study was designed to indicate the cardiotoxicity due to ^99mTc-MIBI injection in myocardial perfusion imaging in wistar Rats. In addition, protective effect of hesperidin/diosmin compound (HDC) against the cardiotoxicity was evaluated. Twenty five male rats were randomly divided into five groups. The rats in Group 1 (control) only received PBS. For Group 2 (HDC only) the rats treated with only HDC. The rats in Group 3 (radiation) received PBS before injection and exposure to 1 mCi ^99mTc-MIBI. The rats in Group 4 (HDC + radiation) treated with HDC before exposure. For Group 5 (radiation + HDC) the rats were exposed and thereafter administered HDC. The Animals of this study were orally administered 100 mg/kg/day of the HDC for 7 days. Then, the rats were sacrificed and afterwards their heart tissues were carefully extracted for biochemical and histopathological evaluations. According to our results in the radiation group, the rate of rupture of cardiomyocyte fibers was higher than other groups, and in some fibers, the presence of lymphocytes was observed. Relative improvement was observed in radiation + HDC group compared to the radiation group and also a small number of cardiomyocyte fibers were torn and in some fibers, the presence of lymphocytes was observed, which was less than the model group. Collagen deposition significantly increased in radiation group compared to control group (P < 0.05). It can be seen that the percentage of collagen deposition decreased substantially in the group treated with HDC before or after radiation compared to radiation group (P < 0.05). The MDA activities significantly reduced (P < 0.05) in both (HDC + radiation) and (radiation + HDC) groups. SOD activity significantly increased in both (radiation + HDC) and (HDC + radiation) groups compared to that of radiation group (P < 0.05). It could be concluded that the HDC is safe and promising useful therapeutic agent in radiation induced cardiotoxicity for patients undergoing nuclear medicine procedures.

Risk of heart failure among colon and rectal cancer survivors: a population-based case-control study

AIMS

This population-based case-control study aims to investigate the occurrence of heart failure (HF) among colon and rectal cancer survivors compared with a cancer-free control population taking into account pre-existing cardiovascular risk factors and the influence of treatment.

METHODS AND RESULTS

Colon and rectal cancer survivors diagnosed between 2007 and 2014 were selected from a linked cohort of cancer and primary care data in the Netherlands and matched based on gender, birth year, general practitioner (GP) practice, and follow-up period to cancer-free controls. The occurrence of HF was identified based on GP recorded diagnoses after index date (diagnosis date for cases). A Cox proportional hazards model was used to estimate hazard ratios (HRs), adjusted for age, sex, hypertension, diabetes, and hypercholesterolaemia. A total of 5333 colon cancer cases and 2468 rectal cancer cases could be matched to a total of 31 204 cancer-free controls. A statistically significant increased risk of HF was seen among all cases compared with cancer-free controls (HR 1.33; 95% confidence interval: 1.12-1.59). This was also seen when analysing colon cancer and rectal cancer separately. Being diagnosed with stage IV cancer, having hypertension, or having hypercholesterolaemia statistically significantly increased the risk of HF among colon cancer. Hypertension was a statistically significant risk factor for developing HF among rectal cancer cases.

CONCLUSIONS

Colon and rectal cancer survivors are at increased risk for developing HF. More awareness should be created by treating physicians and GPs for this potential increased risk in order to further improve survival.

Momordica. charantia-Derived Extracellular Vesicles-Like Nanovesicles Protect Cardiomyocytes Against Radiation Injury via Attenuating DNA Damage and Mitochondria Dysfunction

Thoracic radiotherapy patients have higher risks of developing radiation-induced heart disease (RIHD). Ionizing radiation generates excessive reactive oxygens species (ROS) causing oxidative stress, while Momordica. charantia and its extract have antioxidant activity. Plant-derived extracellular vesicles (EVs) is emerging as novel therapeutic agent. Therefore, we explored the protective effects of Momordica. charantia-derived EVs-like nanovesicles (MCELNs) against RIHD. Using density gradient centrifugation, we successfully isolated MCELNs with similar shape, size, and markers as EVs. Confocal imaging revealed that rat cardiomyocytes H9C2 cells internalized PKH67 labeled MCELNs time-dependently. In vitro assay identified that MCELNs promoted cell proliferation, suppressed cell apoptosis, and alleviated the DNA damage in irradiated (16 Gy, X-ray) H9C2 cells. Moreover, elevated mitochondria ROS in irradiated H9C2 cells were scavenged by MCELNs, protecting mitochondria function with re-balanced mitochondria membrane potential. Furthermore, the phosphorylation of ROS-related proteins was recovered with increased ratios of p-AKT/AKT and p-ERK/ERK in MCELNs treated irradiated H9C2 cells. Last, intraperitoneal administration of MCELNs mitigated myocardial injury and fibrosis in a thoracic radiation mice model. Our data demonstrated the potential protective effects of MCELNs against RIHD. The MCELNs shed light on preventive regime development for radiation-related toxicity.

Quantitative analysis of the effect of radiation on mitochondria structure using coherent diffraction imaging with a clustering algorithm

Radiation damage and a low signal-to-noise ratio are the primary factors that limit spatial resolution in coherent diffraction imaging (CDI) of biomaterials using X-ray sources. Introduced here is a clustering algorithm named ConvRe based on deep learning, and it is applied to obtain accurate and consistent image reconstruction from noisy diffraction patterns of weakly scattering biomaterials. To investigate the impact of X-ray radiation on soft biomaterials, CDI experiments were performed on mitochondria from human embryonic kidney cells using synchrotron radiation. Benefiting from the new algorithm, structural changes in the mitochondria induced by X-ray radiation damage were quantitatively characterized and analysed at the nanoscale with different radiation doses. This work also provides a promising approach for improving the imaging quality of biomaterials with XFEL-based plane-wave CDI.

Prediction of cardiac events following concurrent chemoradiation therapy for non-small-cell lung cancer using FDG PET

OBJECTIVE

No imaging biomarkers are available for the prediction of cardiac events following concurrent chemoradiation therapy (CCRT) for non-small-cell lung cancer (NSCLC). We evaluated whether F-18 fluorodeoxyglucose positron emission tomography (FDG PET) early after CCRT, in addition to cardiac dosimetry, could predict late cardiac events in NSCLC.

METHODS

We retrospectively enrolled 133 consecutive patients with locally advanced, unresectable stage III NSCLC, who underwent FDG PET early after CCRT and survived at least 6 months. The primary endpoint was cardiac event ≥ grade 2 according to the Common Terminology Criteria for Adverse Events (version 5.0). Myocardial FDG uptake was measured and its association with the risk of cardiac events was evaluated.

RESULTS

FDG PET was performed after a median interval of 11 days of completing CCRT. Overall, 42 (32%) patients experienced cardiac events during a median follow-up of 45 months. The mean heart dose, maximum left ventricular (LV) standardized uptake value (SUV), changes in maximum and mean LV SUV, right ventricular uptake, tumor stage, white blood cell count, and diabetes were associated with cardiac events in univariable analysis. In multivariable analysis, maximum LV SUV (cutoff > 12.84; hazard ratio [95% confidence interval] = 2.140 [1.140-4.016]; p = 0.018) was an independent predictor of cardiac events along with the mean heart dose (> 11.1 Gy; 3.646 [1.792-7.417]; p < 0.001) and tumor stage (IIIB; 1.986 [1.056-3.734]; p = 0.033). It remained predictive of cardiac events in those with higher mean heart dose but not in those with lower mean heart dose.

CONCLUSIONS

Early FDG PET after CCRT for NSCLC could aid in predicting late cardiac events, especially in patients with higher mean heart dose.

Early Detection of Cardiac Damage by Two-Dimensional Speckle Tracking Echocardiography After Thoracic Radiation Therapy: Study Protocol for a Prospective Cohort Study

Background

As one of the important treatment methods for cancer patients, radiotherapy may lead to incidental irradiation of the heart, resulting in radiotherapy-induced heart disease (RIHD) arising many years after radiotherapy. While, there are few studies on early subclinical cardiac damage, which may be essential for the protection of late RIHD. To detect and predict RIHD and early subclinical cardiac damage induced by thoracic radiation therapy, based on two-dimensional speckle tracking echocardiography (2D STE) combined with multiple circulating biomarkers and accurate heart dosimetry.

Methods and Analysis

This is a monocentric prospective cohort study in which 104 patients treated for malignant tumors and with cardiac radiation exposure will be included. All participants will be followed for 12 months after radiotherapy. Echocardiography, 2D STE, and blood samples will be underwent at 5-time points (baseline; after completion of RT; 2, 6, and 12 months after RT). Left ventricular ejection fraction (LVEF); global longitudinal, radial, and circumferential strain; diastolic function parameters; creatine kinase (CK); creatine kinase isoenzyme (CK-MB); cardiac troponin T (cTnT); N-terminal pro-B-type natriuretic peptide (NT-proBNP) and hypersensitive C-reactive protein (hs-CRP) will be measured at baseline and every follow-up time. The incidence of major adverse cardiovascular events will be recorded.

Discussion

This study details the protocol and presents the primary limits and advantages of this single-center project. The inclusion of patients began in 2021, and the results are expected to be published in 2023. This study will be allowed to enhance knowledge on detection and prediction of early subclinical cardiac dysfunction induced by thoracic radiation therapy, based on two-dimensional speckle tracking echocardiography (2D STE) combined with circulating biomarkers and accurate heart dosimetry. Furthermore, we will evaluate risk factors of subtle cardiac damage and identify high-risk groups for early heart damage.

Clinical Trial Registration

ClinicalTrials.gov, identifier: NCT04443400.

Puerarin Reduces Radiation-Induced Vascular Endothelial Cell Damage Via miR-34a/Placental Growth Factor

The aim is to explore the protective effects of Puerarin on radiation-induced vascular endothelial cell damage and its underlying mechanism. The apoptosis and DNA damage of Human umbilical vascular endothelial cells (HUVECs) exposed to radiation alone or in combination with glucose in the exposed group were significantly elevated (P < .05) compared with those in the control group. The Puerarin-treated HUVECs showed significant reduction in the radiation-induced apoptosis and DNA damage (P < .05). Furthermore, X-ray irradiation significantly increased the expression of miR-34a, which was reversed by pre-treatment with Puerarin. Placental Growth Factor (PLGF) was a target gene of miR-34a. The expression of PLGF in the peripheral blood of patients receiving radiotherapy significantly increased with an increase in the cumulative dose of radiation (P < .05), after which it began to decrease at the fourth week (P < .05) and then remained at a low level until the end of radiotherapy. Puerarin exerts a radioprotective effect by decreasing DNA damage and apoptosis through miR-34a-targeted PLGF.

MicroRNA-223-3p Protect Against Radiation-Induced Cardiac Toxicity by Alleviating Myocardial Oxidative Stress and Programmed Cell Death via Targeting the AMPK Pathway

Objectives: Radiotherapy improves the survival rate of cancer patients, yet it also involves some inevitable complications. Radiation-induced heart disease (RIHD) is one of the most serious complications, especially the radiotherapy of thoracic tumors, which is characterized by cardiac oxidative stress disorder and programmed cell death. At present, there is no effective treatment strategy for RIHD; in addition, it cannot be reversed when it progresses. This study aims to explore the role and potential mechanism of microRNA-223-3p (miR-223-3p) in RIHD.

Methods: Mice were injected with miR-223-3p mimic, inhibitor, or their respective controls in the tail vein and received a single dose of 20 Gy whole-heart irradiation (WHI) for 16 weeks after 3 days to construct a RIHD mouse model. To inhibit adenosine monophosphate activated protein kinase (AMPK) or phosphodiesterase 4D (PDE4D), compound C (CompC) and AAV9-shPDE4D were used.

Results: WHI treatment significantly inhibited the expression of miR-223-3p in the hearts; furthermore, the levels of miR-223-3p decreased in a radiation time-dependent manner. miR-223-3p mimic significantly relieved, while miR-223-3p inhibitor aggravated apoptosis, oxidative damage, and cardiac dysfunction in RIHD mice. In addition, we found that miR-223-3p mimic improves WHI-induced myocardial injury by activating AMPK and that the inhibition of AMPK by CompC completely blocks these protective effects of miR-223-3p mimic. Further studies found that miR-223-3p lowers the protein levels of PDE4D and inhibiting PDE4D by AAV9-shPDE4D blocks the WHI-induced myocardial injury mediated by miR-223-3p inhibitor.

Conclusion: miR-223-3p ameliorates WHI-induced RIHD through anti-oxidant and anti-programmed cell death mechanisms via activating AMPK by PDE4D regulation. miR-223-3p mimic exhibits potential value in the treatment of RIHD.

Lanzhou Lily polysaccharide fragment protects human umbilical vein endothelial cells from radiation-induced DNA double-strand breaks

Background

Radiotherapy is widely used in the treatment of tumors. However, while killing tumor cells, radiation may also cause damage to the surrounding normal tissues. Therefore, it is very important to find safe and effective radiation protection agents.

Purpose

To investgate the radiation protection effect of Lanzhou Lily polysaccharide fragments (LLP). Methods: The crude polysaccharides of Lanzhou Lily were extracted from the dried bulb powder of Lilium lilium by ultrasonic-assisted hot water method, and then five different fragments were separated from the polysaccharides by DEAE-52-cellulose column. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, neutral comet and immunofluorescent staining were used to investigate the effect of LPe fragment on Human Umbilical Vein Endothelial Cells (HUVEC) survival and the possible radioprotective mechanism.

Results

The LPe fragment (composing of mannose and glucose, with a ratio of 5.5:2.9, and the average molecular weight is 8629.8 Da), significantly promoted the proliferation of HUVECs and protected cells from X-ray-induced double-strand breaks (DSBs) in DNA, in which pretreatment with the LPe fragment at 100 μg/mL showed the most pronounced protection. In addition, the occurrence of X-ray-induced γH2AX foci was significantly reduced by treatment with the LPe fragment at 50, 100, and 200 μg/mL. Furthermore, caffeine or wortmannin in combination with the LPe fragment at 25 μg/mL significantly reduced the number of X-ray-induced γH2AX foci, indicating phosphoinositide-3 kinases (PI3K) is involved in H2AX phosphorylation in HUVECs.

Conclusion

These results indicate the LPe fragment has a protective effect against radiation-induced DSBs and may be used as a natural antioxidant agent.

Socorro SS, Roy GT. Factors affecting overall survival in 51 adult Filipino patients undergoing stereotactic radiosurgery for spine metastases

Objectives

Stereotactic radiosurgery (SRS) is part of the multimodality treatment for patients with cancer. The objective of this study is to determine factors which influence overall survival (OS) of Filipino patients who underwent SRS for metastatic tumors of the spine.

Methods

This is a retrospective analysis of a cohort of Filipino patients treated with spine SRS for metastatic tumors in a single institution. Putative predictors were determined by the institution's spine SRS team and described in the cohort. A Cox proportional hazards regression model was utilized to construct a model based on the predictors determined by the institution's spine SRS team.

Results

A total of 51 consecutive patients with 68 spine metastases were treated with SRS at our institution. The median OS was 13.1 months (95% CI of 7.1 to 19.1). On multivariate analysis, significant predictors that are associated with OS were visceral tumor origin (adjusted HR: 3.08, 95% CI of 1.24 to 7.64, p = 0.015) and cardiovascular disease (adjusted HR: 2.50, 95% CI of 1.04 to 5.94, p = 0.039) with dose and number of fractions as co-variates [Model Wald χ² (5, N = 51) = 11.11 (p = 0.049)].

Conclusions

The presence of visceral tumor origins and cardiovascular disease are independent factors that are associated with lower overall survival in Filipino patients with spine metastasis treated with SRS.

Radiation-induced cardiovascular disease: an overlooked role for DNA methylation?

Radiotherapy in cancer treatment involves the use of ionizing radiation for cancer cell killing. Although radiotherapy has shown significant improvements on cancer recurrence and mortality, several radiation-induced adverse effects have been documented. Of these adverse effects, radiation-induced cardiovascular disease (CVD) is particularly prominent among patients receiving mediastinal radiotherapy, such as breast cancer and Hodgkin's lymphoma patients. A number of mechanisms of radiation-induced CVD pathogenesis have been proposed such as endothelial inflammatory activation, premature endothelial senescence, increased ROS and mitochondrial dysfunction. However, current research seems to point to a so-far unexamined and potentially novel involvement of epigenetics in radiation-induced CVD pathogenesis. Firstly, epigenetic mechanisms have been implicated in CVD pathophysiology. In addition, several studies have shown that ionizing radiation can cause epigenetic modifications, especially DNA methylation alterations. As a result, this review aims to provide a summary of the current literature linking DNA methylation to radiation-induced CVD and thereby explore DNA methylation as a possible contributor to radiation-induced CVD pathogenesis.

Cancer Therapy-Induced Cardiotoxicity-A Metabolic Perspective on Pathogenesis, Diagnosis and Therapy

Long-term cardiovascular complications of cancer therapy are becoming ever more prevalent due to increased numbers of cancer survivors. Cancer therapy-induced cardiotoxicity (CTIC) is an incompletely understood consequence of various chemotherapies, targeted anti-cancer agents and radiation therapy. It is typically detected clinically by a reduction in cardiac left ventricular ejection fraction, assessed by echocardiography. However, once cardiac functional decline is apparent, this indicates irreversible cardiac damage, highlighting a need for the development of diagnostics which can detect CTIC prior to the onset of functional decline. There is increasing evidence to suggest that pathological alterations to cardiac metabolism play a crucial role in the development of CTIC. This review discusses the metabolic alterations and mechanisms which occur in the development of CTIC, with a focus on doxorubicin, trastuzumab, imatinib, ponatinib, sunitinib and radiotherapy. Potential methods to diagnose and predict CTIC prior to functional cardiac decline in the clinic are evaluated, with a view to both biomarker and imaging-based approaches. Finally, the therapeutic potential of therapies which manipulate cardiac metabolism in the context of adjuvant cardioprotection against CTIC is examined. Together, an integrated view of the role of metabolism in pathogenesis, diagnosis and treatment is presented.

Advances in Biomarkers for Detecting Early Cancer Treatment-Related Cardiac Dysfunction

With the gradual prolongation of the overall survival of cancer patients, the cardiovascular toxicity associated with oncology drug therapy and radiotherapy has attracted increasing attention. At present, the main methods to identify early cancer treatment-related cardiac dysfunction (CTRCD) include imaging examination and blood biomarkers. In this review, we will summarize the research progress of subclinical CTRCD-related blood biomarkers in detail. At present, common tumor therapies that cause CTRCD include: (1) Chemotherapy—The CTRCD induced by chemotherapy drugs represented by anthracycline showed a dose-dependent characteristic and most of the myocardial damage is irreversible. (2) Targeted therapy—Cardiovascular injury caused by molecular-targeted therapy drugs such as trastuzumab can be partially or completely alleviated via timely intervention. (3) Immunotherapy—Patients developed severe left ventricular dysfunction who received immune checkpoint inhibitors have been reported. (4) Radiotherapy—CTRCD induced by radiotherapy has been shown to be significantly associated with cardiac radiation dose and radiation volume. Numerous reports have shown that elevated troponin and B-type natriuretic peptide after cancer treatment are significantly associated with heart failure and asymptomatic left ventricular dysfunction. In recent years, a few emerging subclinical CTRCD potential biomarkers have attracted attention. C-reactive protein and ST2 have been shown to be associated with CTRCD after chemotherapy and radiation. Galectin-3, myeloperoxidas, placental growth factor, growth differentiation factor 15 and microRNAs have potential value in predicting CTRCD. In this review, we will summarize CTRCD caused by various tumor therapies from the perspective of cardio-oncology, and focus on the latest research progress of subclinical CTRCD biomarkers.

Investigation of the Antihypertrophic and Antifibrotic Effects of Losartan in a Rat Model of Radiation-Induced Heart Disease

Radiation-induced heart disease (RIHD) is a potential late side-effect of thoracic radiotherapy resulting in left ventricular hypertrophy (LVH) and fibrosis due to a complex pathomechanism leading to heart failure. Angiotensin-II receptor blockers (ARBs), including losartan, are frequently used to control heart failure of various etiologies. Preclinical evidence is lacking on the anti-remodeling effects of ARBs in RIHD, while the results of clinical studies are controversial. We aimed at investigating the effects of losartan in a rat model of RIHD. Male Sprague-Dawley rats were studied in three groups: (1) control, (2) radiotherapy (RT) only, (3) RT treated with losartan (per os 10 mg/kg/day), and were followed for 1, 3, or 15 weeks. At 15 weeks post-irradiation, losartan alleviated the echocardiographic and histological signs of LVH and fibrosis and reduced the overexpression of chymase, connective tissue growth factor, and transforming growth factor-beta in the myocardium measured by qPCR; likewise, the level of the SMAD2/3 protein determined by Western blot decreased. In both RT groups, the pro-survival phospho-AKT/AKT and the phospho-ERK1,2/ERK1,2 ratios were increased at week 15. The antiremodeling effects of losartan seem to be associated with the repression of chymase and several elements of the TGF-β/SMAD signaling pathway in our RIHD model.

Sulforaphane-Mediated Nrf2 Activation Prevents Radiation-Induced Skin Injury through Inhibiting the Oxidative-Stress-Activated DNA Damage and NLRP3 Inflammasome

This article mainly observed the protective effect of sulforaphane (SFN) on radiation-induced skin injury (RISI). In addition, we will discuss the mechanism of SFN's protection on RISI. The RISI model was established by the irradiation of the left thigh under intravenous anesthesia. Thirty-two C57/BL6 mice were randomly divided into control group (CON), SFN group, irradiation (IR) group, and IR plus SFN (IR/SFN) group. At eight weeks after irradiation, the morphological changes of mouse skin tissues were detected by H&E staining. Then, the oxidative stress and inflammatory response indexes in mouse skin tissues, as well as the expression of Nrf2 and its downstream antioxidant genes, were evaluated by ELISA, real-time PCR, and Western blotting. The H&E staining showed the hyperplasia of fibrous tissue in the mouse dermis and hypodermis of the IR group. Western blotting and ELISA results showed that the inflammasome of NLRP3, caspase-1, and IL-1β, as well as oxidative stress damage indicators ROS, 4-HNE, and 3-NT, in the skin tissues of mice in the IR group were significantly higher than those in the control group (p < 0.05). However, the above pathological changes declined sharply after SFN treatment (p < 0.05). In addition, the expressions of Nrf2 and its regulated antioxidant enzymes, including CAT and HO-1, were higher in the skin tissues of SFN and IR/SFN groups, but lower in the control and IR groups (p < 0.05). SFN may be able to suppress the oxidative stress by upregulating the expression and function of Nrf2, and subsequently inhibiting the activation of NLRP3 inflammasome and DNA damage, so as to prevent and alleviate the RISI.

Radiation‑induced dysfunction of energy metabolism in the heart results in the fibrosis of cardiac tissues

Thoracic radiotherapy increases the risk of radiation‑induced heart damage (RIHD); however, the molecular mechanisms underlying these changes are not fully understood. The aim of the present study was to investigate the effects of radiation on the mouse heart using high‑throughput proteomics. Male C57BL/6J mice were used to establish a model of RIHD by exposing the entire heart to 16 Gy high‑energy X‑rays, and cardiac injuries were verified using a cardiac echocardiogram, as well as by measuring serum brain natriuretic peptide levels and conducting H&E and Masson staining 5 months after irradiation. Proteomics experiments were performed using the heart apex of 5‑month irradiated mice and control mice that underwent sham‑irradiation. The most significantly differentially expressed proteins were enriched in 'cardiac fibrosis' and 'energy metabolism'. Next, the cardiac fibrosis and changes to energy metabolism were confirmed using immunohistochemistry staining and western blotting. Extracellular matrix proteins, such as collagen type 1 α 1 chain, collagen type III α 1 chain, vimentin and CCCTC‑binding factor, along with metabolism‑related proteins, such as fatty acid synthase and solute carrier family 25 member 1, exhibited upregulated expression following exposure to ionizing radiation. Additionally, the myocardial mitochondria inner membranes were injured, along with a decrease in ATP levels and the accumulation of lactic acid in the irradiated heart tissues. These results suggest that the high doses of ionizing radiation used lead to structural remodeling, functional injury and fibrotic alterations in the mouse heart. Radiation‑induced mitochondrial damage and metabolic alterations of the cardiac tissue may thus be a pathogenic mechanism of RIHD.

Cardiovascular Manifestations From Therapeutic Radiation: A Multidisciplinary Expert Consensus Statement From the International Cardio-Oncology Society

Radiation therapy is a cornerstone of cancer therapy, with >50% of patients undergoing therapeutic radiation. As a result of widespread use and improved survival, there is increasing focus on the potential long-term effects of ionizing radiation, especially cardiovascular toxicity. Radiation therapy can lead to atherosclerosis of the vasculature as well as valvular, myocardial, and pericardial dysfunction. We present a consensus statement from the International Cardio-Oncology Society based on general principles of radiotherapy delivery and cardiovascular risk assessment and risk mitigation in this population. Anatomical-based recommendations for cardiovascular management and follow-up are provided, and a priority is given to the early detection of atherosclerotic vascular disease on imaging to help guide preventive therapy. Unique management considerations in radiation-induced cardiovascular disease are also discussed. Recommendations are based on the most current literature and represent a unanimous consensus by the multidisciplinary expert panel.

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Radiation therapy leads to short- and long-term cardiovascular adverse effects of the vasculature and the heart, including valvular, myocardial, and pericardial disease.

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Computed tomography scans conducted for radiation planning or cancer staging provide an available opportunity to detect asymptomatic atherosclerosis and direct preventive therapies.

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Additional practical screening recommendations for cardiovascular disease based on anatomical exposure are provided.

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There are unique considerations in the management of radiation-induced cardiovascular disease; contemporary percutaneous treatment is often preferred over surgical options.

A Human 3D Cardiomyocyte Risk Model to Study the Cardiotoxic Influence of X-rays and Other Noxae in Adults

The heart tissue is a potential target of various noxae contributing to the onset of cardiovascular diseases. However, underlying pathophysiological mechanisms are largely unknown. Human stem cell-derived models are promising, but a major concern is cell immaturity when estimating risks for adults. In this study, 3D aggregates of human embryonic stem cell-derived cardiomyocytes were cultivated for 300 days and characterized regarding degree of maturity, structure, and cell composition. Furthermore, effects of ionizing radiation (X-rays, 0.1–2 Gy) on matured aggregates were investigated, representing one of the noxae that are challenging to assess. Video-based functional analyses were correlated to changes in the proteome after irradiation. Cardiomyocytes reached maximum maturity after 100 days in cultivation, judged by α-actinin lengths, and displayed typical multinucleation and branching. At this time, aggregates contained all major cardiac cell types, proven by the patch-clamp technique. Matured and X-ray-irradiated aggregates revealed a subtle increase in beat rates and a more arrhythmic sequence of cellular depolarisation and repolarisation compared to non-irradiated sham controls. The proteome analysis provides first insights into signaling mechanisms contributing to cardiotoxicity. Here, we propose an in vitro model suitable to screen various noxae to target adult cardiotoxicity by preserving all the benefits of a 3D tissue culture.