Mediastinal irradiation and valvular heart disease

Cardiac surgery for radiation associated heart disease in Hodgkin lymphoma patients

Much of the modern focus of Hodgkin's Lymphoma (HL) treatment involves the prevention of secondary organ injury. Despite rationalisations of radiotherapy fields, many patients still develop late radiation-related cardiotoxicity that is severe and requires interventional management. No guidelines exist to direct management of these complex patients who often present with multiple concurrent cardiac pathologies. Despite possessing a greater mortality risk than in the general population, cardiac surgery has an important role in treating radiation-associated heart disease. This review summarises the body of literature surrounding cardiac surgery in HL survivors post-radiotherapy, highlighting the benefits and risks unique to this cohort. The pathophysiology and presentation of radiation-associated heart disease is also explored in relation to HL patients.

The role of cardiac surgery in radiation-associated heart disease: a scoping review

BACKGROUND

Thoracic irradiation is an important tool in the treatment of breast cancer, non-Hodgkin's lymphoma, and other cancers of the chest. The heart is commonly involved in these radiation fields, and young patients can present with severe cardiac pathologies requiring surgical intervention. However, this population poses a high surgical risk due to involvement of mediastinal tissues, and there are no consensus guidelines on best practice management.

AIM

This review aims to summarise the current experience of surgical correction of radiation-associated heart disease. We explore outcomes, technique modifications and alternative therapies for the three primary procedures performed: coronary artery bypass grafting, valvular intervention and pericardiectomy.

METHODS

OVID Medline and PubMed databases were comprehensively searched to identify all studies involving surgery in patients with prior chest radiotherapy. All relevant studies within the past 25 years have been discussed.

CONCLUSION

Irradiated patients have heightened peri-operative risk, but other than redo surgery, these operations are not as treacherous as once thought. Involvement of all layers of the heart, especially the myocardium, is such that long-term mortality suffers despite optimal surgical correction. The goal of surgery in this cohort should be for a quick and safe operation, rather than a technically difficult procedure aimed at longevity.

Cancer survivorship at heart: a multidisciplinary cardio-oncology roadmap for healthcare professionals

In cancer, a patient is considered a survivor from the time of initial diagnosis until the end of life. With improvements in early diagnosis and treatment, the number of cancer survivors (CS) has grown considerably and includes: (1) Patients cured and free from cancer who may be at risk of late-onset cancer therapy-related cardiovascular toxicity (CTR-CVT); (2) Patients with long-term control of not-curable cancers in whom CTR-CVT may need to be addressed. This paper highlights the importance of the cancer care continuum, of a patient-centered approach and of a prevention-oriented policy. The ultimate goal is a personalized care of CS, achievable only through a multidisciplinary-guided survivorship care plan, one that replaces the fragmented management of current healthcare systems. Collaboration between oncologists and cardiologists is the pillar of a framework in which primary care providers and other specialists must be engaged and in which familial, social and environmental factors are also taken into account.

An Overview of Sport Participation and Exercise Prescription in Mitral Valve Disease

The incidence of heart valve disease (HVD) has been rising over the last few decades, mainly due to the increasing average age of the general population, and mitral valve (MV) disease is the second most prevalent HVD after calcific aortic stenosis, but MV disease is a heterogeneous group of different pathophysiological diseases. It is widely proven that regular physical activity reduces all-cause mortality rates, and exercise prescription is part of the medical recommendations for patients affected by cardiovascular diseases. However, changes in hemodynamic balance during physical exercise (including the increase in heart rate, preload, or afterload) could favor the progression of the MV disease and potentially trigger major cardiac events. In young patients with HVD, it is therefore important to define criteria for allowing competitive sport or exercise prescription, balancing the positive effects as well as the potential risks. This review focuses on mitral valve disease pathophysiology, diagnosis, risk stratification, exercise prescription, and competitive sport participation selection, and offers an overview of the principal mitral valve diseases with the aim of encouraging physicians to embody exercise in their daily practice when appropriate.

Dosiomics-Based Prediction of Radiation-Induced Valvulopathy after Childhood Cancer

Valvular Heart Disease (VHD) is a known late complication of radiotherapy for childhood cancer (CC), and identifying high-risk survivors correctly remains a challenge. This paper focuses on the distribution of the radiation dose absorbed by heart tissues. We propose that a dosiomics signature could provide insight into the spatial characteristics of the heart dose associated with a VHD, beyond the already-established risk induced by high doses. We analyzed data from the 7670 survivors of the French Childhood Cancer Survivors' Study (FCCSS), 3902 of whom were treated with radiotherapy. In all, 63 (1.6%) survivors that had been treated with radiotherapy experienced a VHD, and 57 of them had heterogeneous heart doses. From the heart-dose distribution of each survivor, we extracted 93 first-order and spatial dosiomics features. We trained random forest algorithms adapted for imbalanced classification and evaluated their predictive performance compared to the performance of standard mean heart dose (MHD)-based models. Sensitivity analyses were also conducted for sub-populations of survivors with spatially heterogeneous heart doses. Our results suggest that MHD and dosiomics-based models performed equally well globally in our cohort and that, when considering the sub-population having received a spatially heterogeneous dose distribution, the predictive capability of the models is significantly improved by the use of the dosiomics features. If these findings are further validated, the dosiomics signature may be incorporated into machine learning algorithms for radiation-induced VHD risk assessment and, in turn, into the personalized refinement of follow-up guidelines.

The risk of valvular heart disease in the French Childhood Cancer Survivors' Study: Contribution of dose-volume histogram parameters

BACKGROUND AND PURPOSE

Valvular Heart Disease (VHD) is a known complication of childhood cancer after radiotherapy treatment. However, the dose-volume-effect relationships have not been fully explored.

MATERIALS AND METHODS

We obtained individual heart Dose Volume Histograms (DVH) for survivors of the French Childhood Cancer Survivors Study (FCCSS) who had received radiotherapy. We calculated the Mean Dose to the Heart (MHD) in Gy, as well as the heart DVH parameters (V_{d Gy}, which represents the percentage of heart volume receiving at least d Gy), fixing the thresholds to 0.1 Gy, 5 Gy, 20 Gy, and 40 Gy. We analyzed them furtherly in the subpopulation of the cohort that was treated with a dose lower than 5 Gy (V_0.1Gy|_V5Gy=0%), 20 Gy (V_5Gy|_V20Gy=0%), and 40 Gy (V_20Gy|_V40Gy=0%), respectively. We investigated their role in the occurrence of a VHD in this population-based observational cohort study using the Cox proportional hazard model, adjusting for age at cancer diagnosis and chemotherapy exposure.

RESULTS

Median follow-up was 30.6 years. Eighty-one patients out of the 7462 (1 %) with complete data experienced a severe VHD (grade ≥ 3). The risk of VHD increased along with the MHD, and it was associated with high doses to the heart (V_40Gy < 50 %, hazard ratio (HR) = 7.96, 95 % CI: 4.26-14.88 and V_20Gy|_V40Gy=0% >50 %, HR = 5.03, 95 % CI: [2.35-10.76]). Doses 5-20 Gy to more than 50 % (V_5Gy|_V20Gy=0% >50 %) of the heart induced a marginally non-significant estimated risk. We also observed a remarkable risk increase with attained age.

CONCLUSIONS

Our results provide new insight into the VHD risk that may impact current treatments and long-term follow-up of childhood cancer survivors.

Optimal radiotherapy modality sparing for cardiac valves in left-sided breast cancer

Background

The cardiotoxicity caused by radiotherapy is a critical problem in the treatment of patients with breast cancer. The appropriate radiotherapy modality sparing for cardiac valves in left-sided breast cancer has not been well defined. The aim of this study was thus to compare the dosimetric differences in heart and cardiac valves of 3-dimensional conformal radiotherapy (3D-CRT), fixed-field intensity-modulated radiation therapy (IMRT), and volumetric-modulated arc therapy (VMAT) to find the optimal radiotherapy modality sparing for cardiac valves in patients with left breast cancer.

Methods

From January 5, 2021, to March 15, 2021, 21 patients with left-sided breast cancer postmastectomy were included in this study, and 3 different plans for adjuvant radiation were created using 3D-CRT, IMRT, and VMAT for each patient. All patients received 50 Gy in 25 fractions. The mean dose (D_mean) of the heart; percentage volume of the heart receiving ≥5 Gy (V₅), ≥30 Gy (V₃₀), and ≥40 Gy (V₄₀); and the D_mean and the near-maximum dose (D_0.03cc) of cardiac valves were extracted from dose-volume histograms (DVHs) and compared. The correlations in dosimetric factors between cardiac valves and the whole heart were analyzed.

Results

IMRT significantly decreased the values of V₅, V₃₀, V₄₀, and D_mean in the whole heart compared to 3D-CRT and VMAT (P<0.001). Among the 3 different plans, IMRT had the lowest radiation dose to the D_mean and the D_0.03cc of the aortic valve (1.27 Gy/1.75 Gy), pulmonary valve (3.44 Gy/6.89 Gy), tricuspid valve (1.02 Gy/1.14 Gy), and mitral valve (0.93 Gy/1.00 Gy). Pearson correlation analysis found that local parameters (D_mean and D_0.03cc) within valves were strongly correlated to the global parameters (V₅, V₃₀, V₄₀, and D_mean) of the heart.

Conclusions

This study revealed that IMRT showed the lowest cardiac valves dose compared with 3D-CRT and VMAT in left-sided breast cancer radiotherapy. IMRT might be the optimal modality sparing for cardiac valves in this group of patients. Further studies need to be carried out in order to validate the protective role of IMRT on the cardiac valves.

Cellular Senescence, Aging and Non-Aging Processes in Calcified Aortic Valve Stenosis: From Bench-Side to Bedside

Aortic valve stenosis (AS) is the most common valvular heart disease. The incidence of AS increases with age, however, a significant proportion of elderly people have no significant AS, indicating that both aging and nonaging pathways are involved in the pathomechanism of AS. Age-related and stress-induced cellular senescence accompanied by further active processes represent the key elements of AS pathomechanism. The early stage of aortic valve degeneration involves dysfunction and disruption of the valvular endothelium due to cellular senescence and mechanical stress on blood flow. These cells are replaced by circulating progenitor cells, but in an age-dependent decelerating manner. When endothelial denudation is no longer replaced by progenitor cells, the path opens for focal lipid deposition, initiating subsequent oxidation, inflammation and micromineralisation. Later stages of AS feature a complex active process with extracellular matrix remodeling, fibrosis and calcification. Echocardiography is the gold standard method for diagnosing aortic valve disease, although computed tomography and cardiac magnetic resonance are useful additional imaging methods. To date, no medical treatment has been proven to halt the progression of AS. Elucidation of differences and similarities between vascular and valvular calcification pathomechanisms may help to find effective medical therapy and reduce the increasing health burden of the disease.

Current view on radiation-induced heart disease and methods of its diagnosis

In recent years, cardiologists and cardiovascular surgeons are increasingly encountering radiation-induced heart disease (RIHD) in their practice. This complication is described in literature but is poorly understood and clinically challenging. Radiation therapy (RT) is widely used in the treatment of many cancers. Despite the considerable risk of RT complications, it is used in 20–55% of cancer patients. Radiation-associated cardiotoxicity appears to be delayed, typically 10 to 30 years following treatment. Mediastinal irradiation significantly increases the risk of non-ischemic cardiomyopathy. Recent reviews estimate the prevalence of radiation-induced cardiomyopathy at more than 10%. Therefore, it is important to understand the pathophysiology of RIHD, consider risk factors associated with radiation injury, and detect the condition early.