Dose-Dependent Radiation-Induced Myocardial Damage in Esophageal Cancer Treated With Chemoradiotherapy: A Prospective Cardiac Magnetic Resonance Imaging Study

Quantitative Analysis of Radiation Therapy-Induced Cardiac and Aortic Sequelae in Patients With Lung Cancer via Magnetic Resonance Imaging: A Pilot Study

PURPOSE

The objective of this study was to quantify early radiation therapy (RT)-induced cardiac and aortic changes in patients with lung cancer using cardiac magnetic resonance imaging (MRI).

METHODS AND MATERIALS

Nine patients with lung cancer treated with RT completed MR scans at baseline (before RT) and at 3 and 6 months after RT completion. Cine, T1/T2, late gadolinium enhancement (LGE), and 4-dimensional flow MRIs were acquired to assess biological and mechanical cardiovascular changes globally (ie, over the entire left ventricle (LV) or aorta) and regionally (according to an American Heart Association model).

RESULTS

Regional metrics demonstrated multiple significant changes and dose-dependent responses. Notably, LGE showed changes at 3 and 6 months over septal and high-dose regions (P < .0458). Longitudinal strain changes were notable at septal and high-dose regions at 3 months and at septal regions at 6 months (P < .0469). Elevated T1/T2 signals (P < .0391) and changes in radial/circumferential strain at the septum (P < .0391) were observed at 3 months. Both T1/T2 signal and LGE were correlated with dose at 6 months (T1 signal also at 3 months), with significantly greater changes in regions receiving >50 Gy (P < .0331). LV dose was not correlated with LV strain changes (P > .1), but ascending aortic dose was correlated with strain changes at segments 1 and 2 of the LV (P < .0362). Global metrics identified only 2 significant responses: increase in LGE volume at 6 months and a reduction in ascending aortic circumferential strain at 3 months (P < .0356).

CONCLUSIONS

Early MR-based changes after RT occurred primarily in high-dose regions and the LV septal wall. Although several early signals resolved by 6 months, LGE and longitudinal strain changes persisted for at least 6 months. Dose-dependent responses/correlations were observed for T1/T2/LGE changes at 6 months, with the greatest effect in regions exposed to >50 Gy. Further investigations with larger cohorts and longer follow-up are warranted to confirm regional dose dependence and the association between aortic dose and LV strain observed in this pilot study.

The potential overdose of heart and left anterior descending coronary artery region during intensity-modulated radiation therapy in patients with esophageal cancer

This study aimed to investigate the changes in dose distribution in the heart and left anterior descending coronary artery region (LADR) during intensity-modulated radiation therapy (IMRT) in patients with esophageal cancer (EC) treated at our institution. The heart and LADR were delineated on the initial and off-cord boost planning computed tomography (CT) images. Cardiac volume reduction (CVR) was defined as the reduction in cardiac volume between the initial CT and off-cord boost CT at the dose of 36 Gy irradiated. The involved field IMRT plan was created based on each initial and off-cord boost CT image and was analyzed based on the relationship between CVR and heart and LADR dose-volume parameters (Heart-Dmax, Heart-Dmean, Heart-V20, Heart-V30, Heart-V40, LADR-Dmax, LADR-Dmean, LADR-V15 and LADR-V30). Forty patients with EC were investigated between January 2016 and January 2022. The median CVR ratio during radiation therapy (RT) was 5.57% (range, -7.79 to 18.26%). Simple linear regression analysis revealed significant correlations between CVR during RT and changes in the heart and LADR dose-volume parameters. Some patients (>10%) experienced severe changes in the heart and LADR dose distribution. In three cases with reduced heart volume and primary tumor mass, the changes in LADR-V15 and LADR-V30 showed outliers. In conclusion, CVR during RT correlated with an increase in the heart and LADR dose. When both CVR and tumor volume reduction are large, a potential overdose of LADR during RT should be noted in the IMRT era.

Cardiac volume reduction during radiotherapy in patients with esophageal carcinoma

The present study investigated the factors contributing to cardiac volume reduction (CVR) during radiotherapy (RT) in patients with esophageal carcinoma (EC). This retrospective study included patients with EC treated at National Hospital Organization Shikoku Cancer Center (Matsuyama, Japan). Cardiac delineation was based on initial and off-cord boost (spinal cord-sparing approach) planning computed tomography images. The relationship between CVR and other relevant parameters was analyzed. A total of 58 patients with EC were investigated between January 2016 and January 2022. Univariate and multiple regression analyses revealed a statistically significant association between CVR during RT and the change ratio of the inferior vena cava (IVC) volume and body mass index (BMI) loss. In multivariate analysis of CVR of >10%, only the change in IVC volume exhibited a significant association. Conversely, CVR during RT displayed no association with heart dose-volume parameters, laboratory data, or changes in blood pressure and pulse rate. Among the 12 cases with CVR of >10%, the median movement of the left anterior descending coronary artery region (LADR) was 1.35 cm (range, 0.0-2.7 cm). In conclusion, CVR during RT was most strongly associated with changes in IVC volume, suggesting dehydration as the primary cause, rather than radiation-induced heart damage. LADR movement due to a CVR of >10% may lead to LADR radiation overdose.

Identification of key genes in sepsis-induced cardiomyopathy based on integrated bioinformatical analysis and experiments in vitro and in vivo

Introduction

Sepsis is a life-threatening disease that damages multiple organs and induced by the host's dysregulated response to infection with high morbidity and mortality. Heart remains one of the most vulnerable targets of sepsis-induced organ damage, and sepsis-induced cardiomyopathy (SIC) is an important factor that exacerbates the death of patients. However, the underlying genetic mechanism of SIC disease needs further research.

Methods

The transcriptomic dataset, GSE171564, was downloaded from NCBI for further analysis. Gene expression matrices for the sample group were obtained by quartile standardization and log2 logarithm conversion prior to analysis. The time series, protein-protein interaction (PPI) network, and functional enrichment analysis via Gene Ontology and KEGG Pathway Databases were used to identify key gene clusters and their potential interactions. Predicted miRNA-mRNA relationships from multiple databases facilitated the construction of a TF-miRNA-mRNA regulatory network. In vivo experiments, along with qPCR and western blot assays, provided experimental validation.

Results

The transcriptome data analysis between SIC and healthy samples revealed 221 down-regulated, and 342 up-regulated expressed genes across two distinct clusters. Among these, Tpt1, Mmp9 and Fth1 were of particular significance. Functional analysis revealed their role in several biological processes and pathways, subsequently, in vivo experiments confirmed their overexpression in SIC samples. Notably, we found TPT1 play a pivotal role in the progression of SIC, and silencing TPT1 showed a protective effect against LPS-induced SIC.

Conclusion

In our study, we demonstrated that Tpt1, Mmp9 and Fth1 have great potential to be biomarker of SIC. These findings will facilitated to understand the occurrence and development mechanism of SIC.

Radiotherapy-induced diffuse myocardial fibrosis in early-stage breast cancer patients - multimodality imaging study with six-year follow-up

BACKGROUND

Breast radiotherapy (RT) induces diffuse myocardial changes, which may increase the incidence of heart failure with preserved ejection fraction. This study aimed to evaluate the early signs of diffuse fibrosis after RT and their evolution during a six-year follow-up.

METHODS

Thirty patients with early-stage left-sided breast cancer were studied with echocardiography and electrocardiography (ECG) at baseline, after RT, and at three-year and six-year follow-up visits. Echocardiography analysis included an off-line analysis of integrated backscatter (IBS). ECG was analysed for fragmented QRS (fQRS). In addition, cardiac magnetic resonance (CMR) imaging was performed at the six-year control. The left ventricle 16-segment model was used in cardiac imaging, and respective local radiation doses were analysed.

RESULTS

Regional myocardial reflectivity in inferoseptal segments increased by 2.02 (4.53) dB (p = 0.026) and the percentage of leads with fQRS increased from 9.2 to 16.4% (p = 0.002) during the follow-up. In CMR imaging, abnormal extracellular volume (ECV) and T1 mapping values were found with anteroseptal and apical localization in a median of 3.5 (1.00-5.75) and 3 (1.25-4.00) segments, respectively. A higher left ventricle radiation dose was associated with an increased likelihood of having changes simultaneously in CMR and echocardiography (OR 1.26, 95% Cl. 1.00-1.59, p = 0.047).

CONCLUSIONS

After radiotherapy, progressive changes in markers of diffuse myocardial fibrosis were observed in a multimodal manner in ECG and echocardiography. Changes in echocardiography and abnormal values in CMR were localized in the septal and apical regions, and multiple changes were associated with higher radiation doses.

Clinical impact of radiation-induced myocardial damage detected by cardiac magnetic resonance imaging and dose-volume histogram parameters of the left ventricle as prognostic factors of cardiac events after chemoradiotherapy for esophageal cancer

This prospective study aimed to evaluate whether radiation (RT)-induced myocardial damage by cardiac magnetic resonance (CMR) imaging could be a predictor of cardiac events after chemoradiotherapy (CRT) for esophageal cancer and determine the dose-volume histogram (DVH) parameters of the left ventricle (LV) in predicting cardiac events. CMR imaging was performed before and 6 months after CRT in patients receiving definitive CRT. RT-induced myocardial damage was defined as abnormal CMR findings indicating myocardial fibrosis corresponding to an isodose line of ≥30 Gy. The cutoff values of the LV DVH parameters were calculated using the receiver operating characteristic curve based on the presence of RT-induced myocardial damage. The prognostic factors related to cardiac events of Grade 3 or higher were examined. Twenty-three patients were enrolled in the study. RT-induced myocardial damage by late gadolinium enhancement and/or an increase of 100 ms or higher in native T1 post-CRT was detected in 10 of the 23 patients. LV V45 was the best predictive factor for RT-induced myocardial damage with a cutoff value of 2.1% and an area under the curve of 0.75. The median follow-up period was 82.1 months. The 5- and 7-year cumulative incidences of cardiac events of Grade 3 or higher were 14.7 and 22.4%, respectively. RT-induced myocardial damage and LV V45 were significant risk factors (P = 0.015 and P = 0.013, respectively). RT-induced myocardial damage is a significant predictor of cardiac events. LV V45 is associated with RT-induced myocardial damage and subsequent cardiac events.

Quantitative assessment of radiotherapy-induced myocardial damage using MRI: a systematic review

PURPOSE

To determine the role of magnetic resonance imaging (MRI)-based metrics to quantify myocardial toxicity following radiotherapy (RT) in human subjects through review of current literature.

METHODS

Twenty-one MRI studies published between 2011-2022 were identified from available databases. Patients received chest irradiation with/without other treatments for various malignancies including breast, lung, esophageal cancer, Hodgkin's, and non-Hodgkin's lymphoma. In 11 longitudinal studies, the sample size, mean heart dose, and follow-up times ranged from 10-81 patients, 2.0-13.9 Gy, and 0-24 months after RT (in addition to a pre-RT assessment), respectively. In 10 cross-sectional studies, the sample size, mean heart dose, and follow-up times ranged from 5-80 patients, 2.1-22.9 Gy, and 2-24 years from RT completion, respectively. Global metrics of left ventricle ejection fraction (LVEF) and mass/dimensions of cardiac chambers were recorded, along with global/regional values of T1/T2 signal, extracellular volume (ECV), late gadolinium enhancement (LGE), and circumferential/radial/longitudinal strain.

RESULTS

LVEF tended to decline at >20 years follow-up and in patients treated with older RT techniques. Changes in global strain were observed after shorter follow-up (13±2 months) for concurrent chemoradiotherapy. In concurrent treatments with longer follow-up (8.3 years), increases in left ventricle (LV) mass index were correlated with LV mean dose. In pediatric patients, increases in LV diastolic volume were correlated with heart/LV dose at 2 years post-RT. Regional changes were observed earlier post-RT. Dose-dependent responses were reported for several parameters, including: increased T1 signal in high-dose regions, a 0.136% increase of ECV per Gy, progressive increase of LGE with increasing dose at regions receiving >30 Gy, and correlation between increases in LV scarring volume and LV mean/V10/V25 Gy dose.

CONCLUSION

Global metrics only detected changes over longer follow-up, in older RT techniques, in concurrent treatments, and in pediatric patients. In contrast, regional measurements detected myocardial damage at shorter follow-up and in RT treatments without concurrent treatment and had greater potential for dose-dependent response. The early detection of regional changes suggests the importance of regional quantification of RT-induced myocardial toxicity at early stages, before damage becomes irreversible. Further works with homogeneous cohorts are required to examine this matter.

Quantitative assessment of intra- and inter-modality deformable image registration of the heart, left ventricle, and thoracic aorta on longitudinal 4D-CT and MR images

Purpose

Magnetic resonance imaging (MRI)‐based investigations into radiotherapy (RT)‐induced cardiotoxicity require reliable registrations of magnetic resonance (MR) imaging to planning computed tomography (CT) for correlation to regional dose. In this study, the accuracy of intra‐ and inter‐modality deformable image registration (DIR) of longitudinal four‐dimensional CT (4D‐CT) and MR images were evaluated for heart, left ventricle (LV), and thoracic aorta (TA).

Methods and materials

Non‐cardiac‐gated 4D‐CT and T1 volumetric interpolated breath‐hold examination (T1‐VIBE) MRI datasets from five lung cancer patients were obtained at two breathing phases (inspiration/expiration) and two time points (before treatment and 5 weeks after initiating RT). Heart, LV, and TA were manually contoured. Each organ underwent three intramodal DIRs ((A) CT modality over time, (B) MR modality over time, and (C) MR contrast effect at the same time) and two intermodal DIRs ((D) CT/MR multimodality at same time and (E) CT/MR multimodality over time). Hausdorff distance (HD), mean distance to agreement (MDA), and Dice were evaluated and assessed for compliance with American Association of Physicists in Medicine (AAPM) Task Group (TG)‐132 recommendations.

Results

Mean values of HD, MDA, and Dice under all registration scenarios for each region of interest ranged between 8.7 and 16.8 mm, 1.0 and 2.6 mm, and 0.85 and 0.95, respectively, and were within the TG‐132 recommended range (MDA < 3 mm, Dice > 0.8). Intramodal DIR showed slightly better results compared to intermodal DIR. Heart and TA demonstrated higher registration accuracy compared to LV for all scenarios except for HD and Dice values in Group A. Significant differences for each metric and tissue of interest were noted between Groups B and D and between Groups B and E. MDA and Dice significantly differed between LV and heart in all registrations except for MDA in Group E.

Conclusions

DIR of the heart, LV, and TA between non‐cardiac‐gated longitudinal 4D‐CT and MRI across two modalities, breathing phases, and pre/post‐contrast is acceptably accurate per AAPM TG‐132 guidelines. This study paves the way for future evaluation of RT‐induced cardiotoxicity and its related factors using multimodality DIR.