Doxorubicin Effect on Myocardial Metabolism as a Prerequisite for Subsequent Development of Cardiac Toxicity: A Translational 18F-FDG PET/CT Observation

Prediabetes is associated with increased cardiac events in patients with cancer who are prescribed anthracyclines

BACKGROUND

Prediabetes, which is a precedent of overt diabetes, is a known risk factor for adverse cardiovascular outcomes. Its impact on adverse cardiovascular outcomes in patients with cancer who are prescribed anthracycline-containing chemotherapy (ACT) is uncertain. The objective of this study was to evaluate the association of prediabetes with cardiovascular events in patients with cancer who are prescribed ACT.

METHODS

The authors identified patients with cancer who received ACT from 2000 to 2019 from Clinical Data Analysis Reporting System of Hong Kong. Patients were divided into diabetes, prediabetes, and normoglycemia groups based on their baseline glycemic profile. The Primary outcome, a major adverse cardiovascular event (MACE), was the composite event of hospitalization for heart failure and cardiovascular death.

RESULTS

Among 12,649 patients at baseline, 3997 had prediabetes, and 5622 had diabetes. Over median follow-up of 8.7 years, the incidence of MACE was 211 (7.0%) in the normoglycemia group, 358 (9.0%) in the prediabetes group, and 728 (12.9%) in the diabetes group. Compared with normoglycemia, prediabetes (adjusted hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.01-1.43) and diabetes (adjusted HR, 1.46; 95% CI, 1.24-1.70) were associated with an increased risk of MACE. In the prediabetes group, 475 patients (18%) progressed to overt diabetes and exhibited a greater risk of MACE (adjusted HR, 1.76; 95% CI, 1.31-2.36) compared with patients who remained prediabetic.

CONCLUSIONS

In patients with cancer who received ACT, those who had prediabetes at baseline and those who progressed to diabetes at follow-up had an increased risk of MACE. The optimization of cardiovascular risk factor management, including prediabetes, should be considered in patients with cancer who are treated before and during ACT to reduce cardiovascular risk.

PLAIN LANGUAGE SUMMARY

Patients with cancer who have preexisting diabetes have a higher risk of cardiovascular events, and prediabetes is often overlooked. In this study of 12,649 patients with cancer identified in the Clinical Data Analysis Reporting System of Hong Kong who were receiving treatment with anthracycline drugs, prediabetes was correlated with increased deaths from cardiovascular disease and/or hospitalizations for heart failure. Patients who progressed from prediabetes to diabetes within 2 years had an increased risk of combined hospitalization for heart failure and death from cardiovascular disease. These findings indicate the importance of paying greater attention to cardiovascular risk factors, including how prediabetes is managed, in patients who have cancer and are receiving chemotherapy with anthracyclines, emphasizing the need for surveillance, follow-up strategies, and consideration of prediabetes management in cancer care.

Heartbreaker: Detection and prevention of cardiotoxicity in hematological malignancies

Cancer survivors are at significant risk of cardiovascular (CV) morbidity and mortality; patients with hematologic malignancies have a higher rate of death due to heart failure compared to all other cancer subtypes. The majority of conventional hematologic cancer treatments is associated with increased risk of acute and long-term CV toxicity. The incidence of cancer therapy induced CV toxicity depends on the combination of patient characteristics and on the type, dose, and duration of the therapy. Early diagnosis of CV toxicity, appropriate referral, more specific cardiac monitoring follow-up and timely interventions in target patients can decrease the risk of CV adverse events, the interruption of oncological therapy, and improve the patient's prognosis. Herein, we summarize the CV effects of conventional treatments used in hematologic malignancies with a focus on definitions and incidence of the most common CV toxicities, guideline recommended early detection approaches, and preventive strategies before and during cancer treatments.

Progression of Myocardial 18F-FDG Uptake in a Patient with Cardiotoxicity

The objective of this case report was to present the progression of chemotherapy-induced cardiotoxicity in a patient with lymphoma, highlighting the importance of myocardial fluor-18-fluorodeoxyglucose (18F-FDG) uptake by positron emission tomography coupled with computed tomography (PET/CT). 43-year-old female patient with uterine lymphoma, who underwent hysterectomy followed by three chemotherapy regimens and radiotherapy. The patient had episodes of acute heart failure two years after chemotherapy. Echocardiogram revealed a reduction in left ventricular ejection fraction (LVEF). A retrospective analysis of 18F-FDG PET/CT showed an increase in myocardial uptake in all tests performed during oncologic treatment. Despite disease remission, the patient developed heart failure with reduced LVEF. During chemotherapy, there was a diffuse, significant increase in myocardial 18F-FDG uptake, which preceded the decrease in myocardial performance and seemed to reflect metabolic changes in cardiomyocytes, related to cardiotoxicity. Would an analysis of myocardial 18F-FDG uptake yield a different cardiac outcome in this patient? This question is relevant, considering that other patients may benefit from the use of PET as an early marker of cardiotoxicity. Imaging tests are essential in the follow-up of patients at risk of cardiotoxicity. Although echocardiography remains the main imaging test in the diagnosis of cardiotoxicity, 18F-FDG PET/CT may be a powerful tool for the early diagnosis of this condition.

Robustness of [18F]FDG PET/CT radiomic analysis in the setting of drug-induced cardiotoxicity

BACKGROUND AND OBJECTIVES

Standardization of radiomic data acquisition protocols is still at a very early stage, revealing a strong need to work towards the definition of uniform image processing methodologies The aim of this study is to identify sources of variability in radiomic data derived from image discretization and resampling methodologies prior to image feature extraction. Furthermore, to identify robust potential image-based biomarkers for the early detection of cardiotoxicity.

METHODS

Image post-acquisition processing, interpolation, and volume of interest (VOI) segmentation were performed. Four experiments were conducted to assess the reliability in terms of the intraclass correlation coefficient (ICC) of the radiomic features and the effects of the variation of voxel size and gray level discretization. Statistical analysis was performed separating the patients according to cardiotoxicity diagnosis. Differences of texture features were studied with Mann-Whitney U test. P-values <0.05 after multiple testing correction were considered statistically significant. Additionally, a non-supervised k-Means clustering algorithm was evaluated.

RESULTS

The effect of the variation in the voxel size demonstrated a non-dependency relationship with the values of the radiomic features, regardless of the chosen discretization method. The median ICC values were 0.306 and 0.872 for absolute agreement and consistency, respectively, when varying the discretization bin number. The median ICC values were 0.678 and 0.878 for absolute agreement and consistency, respectively, when varying the discretization bin size. A total of 16 first order, 6 Gray Level Co-occurrence Matrix (GLCM), 4 Gray Level Dependence Matrix (GLDM) and 4 Gray Level Run Length Matrix (GLRLM) features demonstrated statistically significant differences between the diagnosis groups for interim scans (P<0.05) for the fixed bin size (FBS) discretization methodology. However, no statistically significant differences between diagnostic groups were found for the fixed bin number (FBN) discretization methodology. Two clusters based on the radiomic features were identified.

CONCLUSIONS

Gray level discretization has a major impact on the repeatability of the radiomic features. The selection of the optimal processing methodology has led to the identification of texture-based patterns for the differentiation of early cardiac damage profiles.

Molecular Imaging Biomarkers in Cardiooncology: A View on Established Technologies and Future Perspectives

Novel therapeutic options have significantly improved survival and long-term outcomes in many cancer entities. Unfortunately, this improvement in outcome is often accompanied by new and increasingly relevant therapy-related cardiovascular toxicity. In this context, cardiooncology has emerged as a new field of interdisciplinary individual patient care. Important tasks are pretherapeutic risk stratification and early detection and treatment of cardiotoxicity, which comprises cardiac damage in relation to cardiovascular comorbidities, the tumor disease, and cancer treatment. Clinical manifestations can cover a broad spectrum, ranging from subtle and usually asymptomatic abnormalities to serious acute or chronic complications. Typical manifestations include acute and chronic heart failure, myo- and pericarditis, arrythmias, ischemia, and endothelial damage. They can be related to almost all current cancer treatments, including cytotoxic chemotherapy, targeted therapy, immunotherapy, hormonal therapy, and radiotherapy. Molecular imaging biomarkers can aid in pretherapeutic cardiooncologic assessment for primary prevention and personalized surveillance, detection, and differential diagnosis of cardiotoxic complications. Potential advantages over conventional diagnostics are the higher detection sensitivity for subtle changes in cardiac homeostasis, higher reproducibility, and better observer independence. Hybrid imaging with highly sensitive PET/MRI may be particularly suited for early diagnosis. Important technologies that are encouraged in current multidisciplinary guidelines are equilibrium radionuclide angiography for evaluation of ventricular function and chamber morphology, as well as myocardial perfusion imaging for additional detection of ischemia. Novel modalities that may detect even earlier signs of cardiotoxicity comprise 123I-metaiodobenzylguanidine SPECT to visualize sympathetic innervation, 18F-FDG and somatostatin receptor (68Ga-DOTATOC/DOTATATE) PET to indicate a metabolic shift and inflammation, and 68Ga-fibroblast activation protein inhibitor PET to monitor cardiac remodeling. In addition, PET imaging of mitochondrial function has recently been introduced in preclinical models and will potentially broaden the field of application through higher sensitivity and specificity and by enabling higher individualization of diagnostic concepts.

Right ventricle toxicity in cancer treatment: a focused review on cardiac imaging

Background: The right ventricle (RV) remains the 'forgotten chamber' in the clinical assessment of cancer therapy-related cardiac dysfunction (CTRCD). Aim: We aimed to review the role that various cardiac imaging modalities play in RV assessment as part of the integrative management of patients undergoing cancer therapy. Discussion: RV assessment remains challenging by traditional 2D echocardiography. In this review we discuss other parameters such as right atrial strain, and other echocardiographic modalities such as 3D and stress echocardiography. We also elaborate on the specific role that cardiac magnetic resonance imaging and equilibrium radionuclide angiocardiography can play in assessing the RV. Conclusion: Biventricular function should be monitored following chemotherapy for early detection of subclinical CTRCD and possible solitary RV changes.

Divergent Oxidative Stress in Normal Tissues and Inflammatory Cells in Hodgkin and Non-Hodgkin Lymphoma

BACKGROUND

Previous studies reported mitochondrial and endoplasmic reticulum redox stress in peripheral blood mononucleated cells (PBMCs) of treatment-naïve Hodgkin lymphoma (HL) patients. Here, we assessed whether this response also applies to non-HL (NHL) patients, and whether the oxidative damage is a selective feature of PBMCs or, rather, also affects tissues not directly involved in the inflammatory response.

METHODS

Isolated PBMCs of 28 HL, 9 diffuse large B cell lymphoma, 8 less aggressive-NHL, and 45 controls underwent flow cytometry to evaluate redox stress and uptake of the glucose analogue 2-NBDG. This analysis was complemented with the assay of malondialdehyde (MDA) levels and enzymatic activity of glucose-6P-dehydrogenase and hexose-6P-dehydrogenase (H6PD). In all lymphoma patients, ¹⁸F-fluoro-deoxyglucose uptake was estimated in the myocardium and skeletal muscles.

RESULTS

Mitochondrial reactive oxygen species generation and MDA levels were increased only in HL patients as well as H6PD activity and 2-NBDG uptake. Similarly, myocardial FDG retention was higher in HL than in other groups as opposed to a similar tracer uptake in the skeletal muscle.

CONCLUSIONS

Redox stress of PBMCs is more pronounced in HL with respect to both NHL groups. This phenomenon is coherent with an increased activity of H6PD that also extends to the myocardium.

Demonstration of the Early Cardiac Bioavailability of a Non-Specific Cell-Targeted Peptide Using Radionuclide-Based Imaging In Vivo

The cardiac bioavailability of peptide drugs that inhibit harmful intracellular protein-protein interactions in cardiovascular diseases remains a challenging task in drug development. This study investigates whether a non-specific cell-targeted peptide drug is available in a timely manner at its intended biological destination, the heart, using a combined stepwise nuclear molecular imaging approach. An octapeptide (heart8P) was covalently coupled with the trans-activator of transcription (TAT) protein transduction domain residues 48-59 of human immunodeficiency virus-1 (TAT-heart8P) for efficient internalization into mammalian cells. The pharmacokinetics of TAT-heart8P were evaluated in dogs and rats. The cellular internalization of TAT-heart8P-Cy(5.5) was examined on cardiomyocytes. The real-time cardiac delivery of ⁶⁸Ga-NODAGA-TAT-heart8P was tested in mice under physiological and pathological conditions. Pharmacokinetic studies of TAT-heart8P in dogs and rats revealed a fast blood clearance, high tissue distribution, and high extraction by the liver. TAT-heart-8P-Cy(5.5) was rapidly internalized in mouse and human cardiomyocytes. Correspondingly, organ uptake of hydrophilic ⁶⁸Ga-NODAGA-TAT-heart8P occurred rapidly after injection with an initial cardiac bioavailability already 10 min post-injection. The saturable cardiac uptake was revailed by the pre-injection of the unlabeled compound. The cardiac uptake of ⁶⁸Ga-NODAGA-TAT-heart8P did not change in a model of cell membrane toxicity. This study provides a sequential stepwise workflow to evaluate the cardiac delivery of a hydrophilic, non-specific cell-targeting peptide. ⁶⁸Ga-NODAGA-TAT-heart8P showed rapid accumulation in the target tissue early after injection. The implementation of PET/CT radionuclide-based imaging methodology as a means to assess effective and temporal cardiac uptake represents a useful and critical application in drug development and pharmacological research and can be extended to the evaluation of comparable drug candidates.

Anthracycline cardiotoxicity: current methods of diagnosis and possible role of 18F-FDG PET/CT as a new biomarker

Despite advances in chemotherapy, the drugs used in cancer treatment remain rather harmful to the cardiovascular system, causing structural and functional cardiotoxic changes. Positron-emission tomography associated with computed tomography (PET/CT) has emerged like a promising technique in the early diagnosis of these adverse drug effects as the myocardial tissue uptake of fluorodeoxyglucose labeled with fluorine-18 (¹⁸F-FDG), a glucose analog, is increased after their use. Among these drugs, anthracyclines are the most frequently associated with cardiotoxicity because they promote heart damage through DNA breaks, and induction of an oxidative, proinflammatory, and toxic environment. This review aimed to present the scientific evidence available so far regarding the use of ¹⁸F-FDG PET/CT as an early biomarker of anthracycline-related cardiotoxicity. Thus, it discusses the physiological basis for its uptake, hypotheses to justify its increase in the myocardium affected by anthracyclines, importance of ¹⁸F-FDG PET/CT findings for cardio-oncology, and primary challenges of incorporating this technique in standard clinical oncology practice.

Nuclear medicine in the assessment and prevention of cancer therapy-related cardiotoxicity: prospects and proposal of use by the European Association of Nuclear Medicine (EANM)

Cardiotoxicity may present as (pulmonary) hypertension, acute and chronic coronary syndromes, venous thromboembolism, cardiomyopathies/heart failure, arrhythmia, valvular heart disease, peripheral arterial disease, and myocarditis. Many of these disease entities can be diagnosed by established cardiovascular diagnostic pathways. Nuclear medicine, however, has proven promising in the diagnosis of cardiomyopathies/heart failure, and peri- and myocarditis as well as arterial inflammation. This article first outlines the spectrum of cardiotoxic cancer therapies and the potential side effects. This will be complemented by the definition of cardiotoxicity using non-nuclear cardiovascular imaging (echocardiography, CMR) and biomarkers. Available nuclear imaging techniques are then presented and specific suggestions are made for their application and potential role in the diagnosis of cardiotoxicity.

Mechanisms and Drug Intervention for Doxorubicin-Induced Cardiotoxicity Based on Mitochondrial Bioenergetics

Doxorubicin (DOX) is an anthracycline chemotherapy drug, which is indispensable in antitumor therapy. However, its subsequent induction of cardiovascular disease (CVD) has become the primary cause of mortality in cancer survivors. Accumulating evidence has demonstrated that cardiac mitochondrial bioenergetics changes have become a significant marker for doxorubicin-induced cardiotoxicity (DIC). Here, we mainly summarize the related mechanisms of DOX-induced cardiac mitochondrial bioenergetics disorders reported in recent years, including mitochondrial substrate metabolism, the mitochondrial respiratory chain, myocardial ATP storage and utilization, and other mechanisms affecting mitochondrial bioenergetics. In addition, intervention for DOX-induced cardiac mitochondrial bioenergetics disorders using chemical drugs and traditional herbal medicine is also summarized, which will provide a comprehensive process to study and develop more appropriate therapeutic strategies for DIC.

Anthracycline-induced cardiotoxicity: From pathobiology to identification of molecular targets for nuclear imaging

Anthracyclines are a widely used class of chemotherapy in pediatric and adult cancers, however, their use is hampered by the development of cardiotoxic side-effects and ensuing complications, primarily heart failure. Clinically used imaging modalities to screen for cardiotoxicity are mostly echocardiography and occasionally cardiac magnetic resonance imaging. However, the assessment of diastolic and global or segmental systolic function may not be sensitive to detect subclinical or early stages of cardiotoxicity. Multiple studies have scrutinized molecular nuclear imaging strategies to improve the detection of anthracycline-induced cardiotoxicity. Anthracyclines can activate all forms of cell death in cardiomyocytes. Injury mechanisms associated with anthracycline usage include apoptosis, necrosis, autophagy, ferroptosis, pyroptosis, reactive oxygen species, mitochondrial dysfunction, as well as cardiac fibrosis and perturbation in sympathetic drive and myocardial blood flow; some of which have been targeted using nuclear probes. This review retraces the pathobiology of anthracycline-induced cardiac injury, details the evidence to date supporting a molecular nuclear imaging strategy, explores disease mechanisms which have not yet been targeted, and proposes a clinical strategy incorporating molecular imaging to improve patient management.

Test-retest repeatability and interobserver variation of healthy tissue metabolism using 18F-FDG PET/CT of the thorax among lung cancer patients

OBJECTIVES

The aim of this study was to assess the test-retest repeatability and interobserver variation in healthy tissue (HT) metabolism using 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) PET/computed tomography (PET/CT) of the thorax in lung cancer patients.

METHODS

A retrospective analysis was conducted in 22 patients with non-small cell lung cancer who had two PET/CT scans of the thorax performed 3 days apart with no interval treatment. The maximum, mean and peak standardized uptake values (SUVs) in different HTs were measured by a single observer for the test-retest analysis and two observers for interobserver variation. Bland-Altman plots were used to assess the repeatability and interobserver variation. Intrasubject variability was evaluated using within-subject coefficients of variation (wCV).

RESULTS

The wCV of test-retest SUVmean measurements in mediastinal blood pool, bone marrow, skeletal muscles and lungs was less than 20%. The left ventricle (LV) showed higher wCV (>60%) in all SUV parameters with wide limits of repeatability. High interobserver agreement was found with wCV of less than 10% in SUVmean of all HT, but up to 22% was noted in the LV.

CONCLUSION

HT metabolism is stable in a test-retest scenario and has high interobserver agreement. SUVmean was the most stable metric in organs with low FDG uptake and SUVpeak in HTs with moderate uptake. Test-retest measurements in LV were highly variable irrespective of the SUV parameters used for measurements.

Aumento de Captação Cardíaca de 18F-FDG Induzida por Quimioterapia em Pacientes com Linfoma: Um Marcador Precoce de Cardiotoxicidade?

Fundamento

Ainda não está estabelecido se a captação de fluorodesoxiglicose no miocárdio ocorre exclusivamente por características fisiológicas ou se representa um desarranjo metabólico causado pela quimioterapia.

Objetivo

Investigar os efeitos da quimioterapia no coração dos pacientes com linfoma por tomografia por emissão de pósitrons associada a tomografia computadorizada (PET/CT) com 2-[18F]-fluoro-2-desoxi-D-glicose (¹⁸F-FDG PET/CT) antes, durante e/ou após a quimioterapia.

Métodos

Setenta pacientes com linfoma submetidos a ¹⁸F-FDG PET/CT foram retrospectivamente analisados. O nível de significância foi de 5%. A captação de ¹⁸F-FDG foi avaliada por três medidas: captação máxima no ventrículo esquerdo ( standardized uptake value , SUV max), razão SUV cardíaco / aorta e SUV cardíaco / SUV no fígado. Também foram comparados peso corporal, glicemia de jejum, tempo pós-injeção e dose administrada de ¹⁸F-FDG entre os exames.

Resultados

A idade média foi de 50,4 ± 20,1 anos e 50% dos pacientes eram mulheres. A análise foi realizada em dois grupos – PET/CT basal vs. intermediário e PET/CT basal vs pós-terapia. Não houve diferença significativa entre as variáveis clínicas e do protocolo dos exames entre os diferentes momentos avaliados. Nós observamos um aumento na SUV máxima no ventrículo esquerdo de 3,5±1,9 (basal) para 5,6±4,0 (intermediário), p=0,01, e de 4,0±2,2 (basal) para 6,1±4,2 (pós-terapia), p<0,001. Uma porcentagem de aumento ≥30% na SUV máxima no ventrículo esquerdo ocorreu em mais da metade da amostra. O aumento da SUV cardíaca foi acompanhado por um aumento na razão SUV máxima no ventrículo esquerdo / SUV máxima na aorta e SUV média no ventrículo esquerdo /SUV média no fígado.

Conclusão

O estudo mostrou um aumento evidente na captação cardíaca de ¹⁸F-FDG em pacientes com linfoma, durante e após quimioterapia. A literatura corrobora com esses achados e sugere que a ¹⁸F-FDG PET/CT pode ser um exame de imagem sensível e confiável para detectar sinais metabólicos precoces de cardiotoxicidade.

Understanding Anthracycline Cardiotoxicity From Mitochondrial Aspect

Anthracyclines, such as doxorubicin, represent one group of chemotherapy drugs with the most cardiotoxicity. Despite that anthracyclines are capable of treating assorted solid tumors and hematological malignancies, the side effect of inducing cardiac dysfunction has hampered their clinical use. Currently, the mechanism underlying anthracycline cardiotoxicity remains obscure. Increasing evidence points to mitochondria, the energy factory of cardiomyocytes, as a major target of anthracyclines. In this review, we will summarize recent findings about mitochondrial mechanism during anthracycline cardiotoxicity. In particular, we will focus on the following aspects: 1) the traditional view about anthracycline-induced reactive oxygen species (ROS), which is produced by mitochondria, but in turn causes mitochondrial injury. 2) Mitochondrial iron-overload and ferroptosis during anthracycline cardiotoxicity. 3) Autophagy, mitophagy and mitochondrial dynamics during anthracycline cardiotoxicity. 4) Anthracycline-induced disruption of cardiac metabolism.

New Insights in Early Detection of Anticancer Drug-Related Cardiotoxicity Using Perfusion and Metabolic Imaging

Cardio-oncology requires a good knowledge of the cardiotoxicity of anticancer drugs, their mechanisms, and their diagnosis for better management. Anthracyclines, anti-vascular endothelial growth factor (VEGF), alkylating agents, antimetabolites, anti-human epidermal growth factor receptor (HER), and receptor tyrosine kinase inhibitors (RTKi) are therapeutics whose cardiotoxicity involves several mechanisms at the cellular and subcellular levels. Current guidelines for anticancer drugs cardiotoxicity are essentially based on monitoring left ventricle ejection fraction (LVEF). However, knowledge of microvascular and metabolic dysfunction allows for better imaging assessment before overt LVEF impairment. Early detection of anticancer drug-related cardiotoxicity would therefore advance the prevention and patient care. In this review, we provide a comprehensive overview of the cardiotoxic effects of anticancer drugs and describe myocardial perfusion, metabolic, and mitochondrial function imaging approaches to detect them before over LVEF impairment.

Future Perspectives of Cardiovascular Biomarker Utilization in Cancer Survivors: A Scientific Statement From the American Heart Association

Improving cancer survival represents the most significant effect of precision medicine and personalized molecular and immunologic therapeutics. Cardiovascular health becomes henceforth a key determinant for the direction of overall outcomes after cancer. Comprehensive tissue diagnostic studies undoubtedly have been and continue to be at the core of the fight against cancer. Will a systemic approach integrating circulating blood-derived biomarkers, multimodality imaging technologies, strategic panomics, and real-time streams of digitized physiological data overcome the elusive cardiovascular tissue diagnosis in cardio-oncology? How can such a systemic approach be personalized for application in day-to-day clinical work, with diverse patient populations, cancer diagnoses, and therapies? To address such questions, this scientific statement approaches a broad definition of the biomarker concept. It summarizes the current literature on the utilization of a multitude of established cardiovascular biomarkers at the intersection with cancer. It identifies limitations and gaps of knowledge in the application of biomarkers to stratify the cardiovascular risk before cancer treatment, monitor cardiovascular health during cancer therapy, and detect latent cardiovascular damage in cancer survivors. Last, it highlights areas in biomarker discovery, validation, and clinical application for concerted efforts from funding agencies, scientists, and clinicians at the cardio-oncology nexus.

An image processing tool for the detection of anthracycline-induced cardiotoxicity by evaluating the myocardial metabolic activity in [18F]FDG PET/CT

Purpose

Chemotherapy-induced cardiotoxicity is one of the main complications during and after cancer treatment. While echocardiography is the most used technique in clinical practice to evaluate left ventricular (LV) dysfunction, a multimodal approach is preferred for the early detection of anthracycline-induced cardiotoxicity. In this paper, an image processing tool allowing the qualitative and quantitative analysis of myocardial metabolic activity by [¹⁸F]fluorodeoxyglucose (FDG) positron emission tomography computed tomography (PET/CT) images, acquired routinely during and after cancer treatment, is presented.

Methods

The methodology is based on cardiac single photon emission computed tomography image processing protocols used in clinical practice. LV polar maps are created, and quantitative regional values are calculated. The tool was validated in a study group of 24 patients with Hodgkin or non-Hodgkin lymphoma (HL and NHL, respectively) treated with anthracyclines. Staging, interim and end-of-treatment [¹⁸F]FDG PET/CT images were acquired and the presented tool was used to extract the quantitative metrics of LV metabolic activity.

Results

Results show an overall increase of metabolic activity in the interim PET image acquired while on treatment compared to staging PET, which then decreased in the end-of-treatment scan. Positive correlation coefficients between staging and interim scans, and negative correlation coefficients between interim and end-of-treatment scans also support this finding. Metabolic changes occur predominantly in the septal region.

Conclusion

The proposed methodology and presented software solution provides the capability to assess quantitatively myocardial metabolism acquired by routine [¹⁸F]FDG PET/CT scanning during cancer treatment for evaluating anthracycline-induced cardiotoxicity. The [¹⁸F]FDG PET/CT septal-lateral uptake ratio is proposed as a new quantitative measure of myocardial metabolism.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11548-021-02508-9

[123I]MIBG is a better early marker of anthracycline cardiotoxicity than [18F]FDG: a preclinical SPECT/CT and simultaneous PET/MR study

Background

During anthracycline treatment of cancer, there is a lack for biomarkers of cardiotoxicity besides the cardiac dysfunction. The objective of the present study was to compare [¹⁸F]FDG and [¹²³I]MIBG (metaiodobenzylguanidine) in a longitudinal study in a doxorubicin-induced cardiotoxicity rat model.

Methods

Male Wistar Han rats were intravenously administered 3 times at 10 days’ interval with saline or doxorubicin (5 mg/kg). [¹²³I]MIBG SPECT/CT (single photon emission computed tomography-computed tomography) and simultaneous [¹⁸F]FDG PET (positron emission tomography)/7 Tesla cardiac MR (magnetic resonance) imaging acquisitions were performed at 24 h interval before first doxorubicin / saline injection and every 2 weeks during 6 weeks. At 6 weeks, the heart tissue was collected for histomorphometry measurements.

Results

At week 4, left ventricle (LV) end-diastolic volume was significantly reduced in the doxorubicin group. At week 6, the decreased LV end-diastolic volume was maintained, and LV end-systolic volume was increased resulting in a significant reduction of LV ejection fraction (47 ± 6% vs. 70 ± 3%). At weeks 4 and 6, but not at week 2, myocardial [¹⁸F]FDG uptake was decreased compared with the control group (respectively, 4.2 ± 0.5%ID/g and 9.2 ± 0.8%ID/g at week 6). Moreover, [¹⁸F]FDG cardiac uptake correlated with cardiac function impairment. In contrast, from week 2, a significant decrease of myocardial [¹²³I]MIBG heart to mediastinum ratio was detected in the doxorubicin group and was maintained at weeks 4 and 6 with a 45.6% decrease at week 6.

Conclusion

This longitudinal study precises that after doxorubicin treatment, cardiac [¹²³I]MIBG uptake is significantly reduced as early as 2 weeks followed by the decrease of the LV end-diastolic volume and [¹⁸F]FDG uptake at 4 weeks and finally by the increase of LV end-systolic volume and decrease of LV ejection fraction at 6 weeks. Cardiac innervation imaging should thus be considered as an early key feature of anthracycline cardiac toxicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00835-1.

Myocardial Metabolic Response Predicts Chemotherapy Curative Potential on Hodgkin Lymphoma: A Proof-of-Concept Study

Genome sharing between cancer and normal tissues might imply a similar susceptibility to chemotherapy toxicity. The present study aimed to investigate whether curative potential of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) is predicted by the metabolic response of normal tissues in patients with Hodgkin lymphoma (HL).

METHODS

According to current guidelines, 86 patients with advanced-stage (IIB-IVB) HL, prospectively enrolled in the HD0607 trial (NCT00795613), underwent 18 F-fluorodeoyglucose PET/CT imaging at diagnosis and, at interim, after two ABVD courses, to decide regimen maintenance or its escalation. In both scans, myocardial FDG uptake was binarized according to its median value. Death and disease relapse were recorded to estimate progression-free survival (PFS) during a follow-up with median duration of 43.8 months (range 6.97-60).

RESULTS

Four patients (4.6%) died, while six experienced disease relapse (7%). Complete switch-off of cancer lesions and cardiac lighting predicted a favorable outcome at Kaplan-Mayer analyses. The independent nature and additive predictive value of their risk prediction were confirmed by the multivariate Cox regression analysis.

CONCLUSION

Susceptibility of HL lesions to chemotherapy is at least partially determined by factors featuring the host who developed it.

Myocardial Glucose Metabolism Is Increased in Newly Diagnosed Lung Adenocarcinoma

BACKGROUND

Cardiac metabolism alterations may be involved in abnormalities of cancer patients' cardiovascular system. This study aimed to explore whether left ventricular myocardial glucose metabolism is altered and its related factors in newly diagnosed patients with lung adenocarcinoma (LAD) who underwent fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT).

METHODS

From our 18F-FDG PET/CT imaging database, 171 patients with newly diagnosed LAD and 43 nononcologic subjects with matched age and sex were retrospectively analyzed. The included patients underwent conventional 18F-FDG PET/CT imaging with a >12-h fasting before 18F-FDG administration. The standardized uptake values (SUVs) of the left ventricular (LV) myocardium, arterial wall, epicardial adipose tissue (EAT), spleen, and bone marrow were separately measured. Laboratory parameters and echocardiographic results were collected as well. LAD patients were divided into 2 groups based on the 95th percentile of LV maximal SUV (SUVmax) obtained from the 43 nononcologic subjects. Univariate analysis and multiple logistic regression analysis were used to identify significant factors.

RESULTS

Higher LV SUVmax was found (3.8 [2.4, 7.7] vs. 3.0 [2.0, 5.4], p = 0.052) in LAD than that in nononcologic patients, whereas no significant differences of 18F-FDG uptake were found in the arterial wall, EAT, spleen, or bone marrow between LAD patients and controls. The maximum diameter (Dmax) of the LAD lesion, SUVmax of spleen, and SUVmax of EAT were related to LV SUVmax in LAD.

CONCLUSIONS

Myocardial glucose metabolism is increased in patients with newly diagnosed LAD. Dmax of LAD lesion, spleen activity, and EAT activity contribute to the increased LV activity in LAD.

Oxidative stress and inflammation: determinants of anthracycline cardiotoxicity and possible therapeutic targets

Chemotherapy with anthracycline-based regimens remains a cornerstone of treatment of many solid and blood tumors but is associated with a significant risk of cardiotoxicity, which can manifest as asymptomatic left ventricular dysfunction or overt heart failure. These effects are typically dose-dependent and cumulative and may require appropriate screening strategies and cardioprotective therapies in order to minimize changes to anticancer regimens or even their discontinuation. Our current understanding of cardiac damage by anthracyclines includes a central role of oxidative stress and inflammation. The identification of these processes through circulating biomarkers or imaging techniques might then be helpful for early diagnosis and risk stratification. Furthermore, therapeutic strategies relieving oxidative stress and inflammation hold promise to prevent heart failure development or at least to mitigate cardiac damage, although further evidence is needed on their efficacy, either alone or as part of combination therapies with neurohormonal antagonists, which are the current adopted standard.

Series of myocardial FDG uptake requiring considerations of myocardial abnormalities in FDG-PET/CT

Distinct from cardiac PET performed with preparation to control physiological FDG uptake in the myocardium, standard FDG-PET/CT performed with 4-6 h of fasting will show variation in myocardial FDG uptake. For this reason, important signs of myocardial and pericardial abnormality revealed by myocardial FDG uptake tend to be overlooked. However, recognition of possible underlying disease will support further patient management to avoid complications due to the disease. This review demonstrates the mechanism of FDG uptake in the myocardium, discusses the factors affecting uptake, and provides notable image findings that may suggest underlying disease.

Nuclear imaging of chemotherapy-induced cardiotoxicity

The high efficiency of modern chemotherapy has made it possible to achieve great success in the treatment of cancer. Cardiovascular adverse effects are a major disadvantage of anticancer therapy, often requiring low and less effective doses or even drug withdrawal. Nuclear imaging techniques are the most sensitive in early detection of left ventricular damage and dysfunction during chemotherapy. This review presents modern data on the potential of nuclear imaging of cardiotoxicity.

Identifying functional metabolic shifts in heart failure with the integration of omics data and a heart-specific, genome-scale model

In diseased states, the heart can shift to use different carbon substrates, measured through changes in uptake of metabolites by imaging methods or blood metabolomics. However, it is not known whether these measured changes are a result of transcriptional changes or external factors. Here, we explore transcriptional changes in late-stage heart failure using publicly available data integrated with a model of heart metabolism. First, we present a heart-specific genome-scale metabolic network reconstruction (GENRE), iCardio. Next, we demonstrate the utility of iCardio in interpreting heart failure gene expression data by identifying tasks inferred from differential expression (TIDEs), which represent metabolic functions associated with changes in gene expression. We identify decreased gene expression for nitric oxide (NO) and N-acetylneuraminic acid (Neu5Ac) synthesis as common metabolic markers of heart failure. The methods presented here for constructing a tissue-specific model and identifying TIDEs can be extended to multiple tissues and diseases of interest.

Metabolic Aspects of Anthracycline Cardiotoxicity

OPINION STATEMENT

Heart failure (HF) is increasingly recognized as the major complication of chemotherapy regimens. Despite the development of modern targeted therapies such as monoclonal antibodies, doxorubicin (DOXO), one of the most cardiotoxic anticancer agents, still remains the treatment of choice for several solid and hematological tumors. The insurgence of cardiotoxicity represents the major limitation to the clinical use of this potent anticancer drug. At the molecular level, cardiac side effects of DOXO have been associated to mitochondrial dysfunction, DNA damage, impairment of iron metabolism, apoptosis, and autophagy dysregulation. On these bases, the antioxidant and iron chelator molecule, dexrazoxane, currently represents the unique FDA-approved cardioprotectant for patients treated with anthracyclines.A less explored area of research concerns the impact of DOXO on cardiac metabolism. Recent metabolomic studies highlight the possibility that cardiac metabolic alterations may critically contribute to the development of DOXO cardiotoxicity. Among these, the impairment of oxidative phosphorylation and the persistent activation of glycolysis, which are commonly observed in response to DOXO treatment, may undermine the ability of cardiomyocytes to meet the energy demand, eventually leading to energetic failure. Moreover, increasing evidence links DOXO cardiotoxicity to imbalanced insulin signaling and to cardiac insulin resistance. Although anti-diabetic drugs, such as empagliflozin and metformin, have shown interesting cardioprotective effects in vitro and in vivo in different models of heart failure, their mechanism of action is unclear, and their use for the treatment of DOXO cardiotoxicity is still unexplored.This review article aims at summarizing current evidence of the metabolic derangements induced by DOXO and at providing speculations on how key players of cardiac metabolism could be pharmacologically targeted to prevent or cure DOXO cardiomyopathy.

Increased myocardial 18F-FDG uptake as a marker of Doxorubicin-induced oxidative stress

BACKGROUND

Oxidative stress and its interference on myocardial metabolism play a major role in Doxorubicin (DXR) cardiotoxic cascade.

METHODS

Mice models of neuroblastoma (NB) were treated with 5 mg DXR/kg, either free (Free-DXR) or encapsulated in untargeted (SL[DXR]) or in NB-targeting Stealth Liposomes (pep-SL[DXR] and TP-pep-SL[DXR]). Control mice received saline. FDG-PET was performed at baseline (PET1) and 7 days after therapy (PET2). At PET2 Troponin-I and NT-proBNP were assessed. Explanted hearts underwent biochemical, histological, and immunohistochemical analyses. Finally, FDG uptake and glucose consumption were simultaneously measured in cultured H9c2 in the presence/absence of Free-DXR (1 μM).

RESULTS

Free-DXR significantly enhanced the myocardial oxidative stress. Myocardial-SUV remained relatively stable in controls and mice treated with liposomal formulations, while it significantly increased at PET2 with respect to baseline in Free-DXR. At this timepoint, myocardial-SUV was directly correlated with both myocardial redox stress and hexose-6-phosphate-dehydrogenase (H6PD) enzymatic activity, which selectively sustain cellular anti-oxidant mechanisms. Intriguingly, in vitro, Free-DXR selectively increased FDG extraction fraction without altering the corresponding value for glucose.

CONCLUSION

The direct correlation between cardiac FDG uptake and oxidative stress indexes supports the potential role of FDG-PET as an early biomarker of DXR oxidative damage.

Association between FDG uptake in the right ventricular myocardium and cancer therapy-induced cardiotoxicity

BACKGROUND

The aim of this study was to investigate changes in myocardial uptake evaluated by oncologic 18F-fluorodeoxyglucose (FDG) PET/CT scans and to determine the relationship between myocardial FDG uptake and cancer therapy-induced cardiotoxicity in breast cancer patients who underwent anthracycline or trastuzumab.

METHODS

We reviewed 121 consecutive patients who underwent oncologic FDG PET/CT and echocardiography at baseline and post-therapy with anthracyclines or trastuzumab for breast cancer. Grade in LV wall, uptake pattern in LV wall, and the presence of RV wall uptake were assessed by visual analysis, and the mean SUV in the LV and RV walls and the change of SUV (ΔSUV) between baseline and post-therapy PET/CT were measured by quantitative analysis. Multiple logistic regression analyses were performed to evaluate the association between PET parameters and cardiotoxicity.

RESULTS

Fifteen patients (12%) showed cardiotoxicity after therapy. The cardiotoxic group tended to show more diffuse LV uptake, higher SUV, and ΔSUV of RV wall than the non-cardiotoxic group following therapy with anthracyclines or trastuzumab. Logistic regression analysis showed that the presence of RV wall uptake, SUV of RV wall (> 1.8), and ΔSUV of RV wall (> 0.4) were significantly associated with cardiotoxicity after controlling for age, radiotherapy, and treatment.

CONCLUSIONS

The presence of RV wall uptake and the increase of SUV of RV wall on post-therapy PET/CT were associated with cardiotoxicity in breast cancer patients who underwent anthracycline or trastuzumab. Oncologic FDG PET/CT scans can provide information regarding cancer therapy-induced cardiotoxicity as well as tumor response.

The anesthetic bupivacaine induces cardiotoxicity by targeting L-type voltage-dependent calcium channels

Objective

Bupivacaine is an amide local anesthetic with possible side effects that include an irregular heart rate. However, the mechanism of bupivacaine-induced cardiotoxicity has not been fully elucidated, thus we aimed to examine this mechanism.

Methods

We performed electrocardiogram recordings to detect action potential waveforms in Sprague Dawley rats after application of bupivacaine, while calcium (Ca²⁺) currents in neonatal rat ventricular cells were examined by patch clamp recording. Western blot and quantitative real-time polymerase chain reaction assays were used to detect the expression levels of targets of interest.

Results

In the present study, after application of bupivacaine, abnormal action potential waveforms were detected in Sprague Dawley rats by electrocardiogram recordings, while decreased Ca²⁺ currents were confirmed in neonatal rat ventricular cells by patch clamp recording. These alterations may be attributed to a deficiency of Ca_V1.3 (L-type) Ca²⁺ channels, which may be regulated by the multifunctional protein calreticulin.

Conclusions

The present study identifies a possible role of the calreticulin–Ca_V1.3 axis in bupivacaine-induced abnormal action potentials and Ca²⁺ currents, which may lead to a better understanding anesthetic drug-induced cardiotoxicity.

Nuclear cardiology in the context of multimodality imaging to detect cardiac toxicity from cancer therapeutics: Established and emerging methods

The complexity of cancer therapies has vastly expanded in the last decade, along with type and severity of cardiac toxicities associated with these treatments. Prevention of pre-clinical cardiotoxicity may improve cardiovascular outcomes and circumvent the decision to place life-sustaining chemotherapeutic agents on hold, making the early detection of cancer therapeutic related cardiac toxicity with non-invasive imaging essential to the care of these patients. There are several established methods of cardiac imaging in the areas of nuclear cardiology, echocardiography, computed tomography, and cardiac magnetic resonance imaging that are used to assess for cardiovascular toxicity of cancer treatments, with several methods under development. The following review will provide an overview of current and emerging imaging techniques in these areas.

Nuclear cardio-oncology: From its foundation to its future

Cardio-oncology is a growing field focused on the prevention and treatment of cardiovascular disease in oncologic patients. While a major focus of chemotherapy-related cardiac dysfunction has been on left ventricular ejection fraction, oncologic treatment can lead to cardiovascular pathology in a variety of ways. The use of multimodality imaging is essential to the care of these patients, with nuclear cardiology playing an important role. We will review nuclear cardiology's history, its current role, and its promising future in cardio-oncology and the management of these patients.

Spinal cord hypermetabolism extends to skeletal muscle in amyotrophic lateral sclerosis: a computational approach to [18F]-fluorodeoxyglucose PET/CT images

PURPOSE

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease leading to neuromuscular palsy and death. We propose a computational approach to [18F]-fluorodeoxyglucose (FDG) PET/CT images to analyze the structure and metabolic pattern of skeletal muscle in ALS and its relationship with disease aggressiveness.

MATERIALS AND METHODS

A computational 3D method was used to extract whole psoas muscle's volumes and average attenuation coefficient (AAC) from CT images obtained by FDG PET/CT performed in 62 ALS patients and healthy controls. Psoas average standardized uptake value (normalized on the liver, N-SUV) and its distribution heterogeneity (defined as N-SUV variation coefficient, VC-SUV) were also extracted. Spinal cord and brain motor cortex FDG uptake were also estimated.

RESULTS

As previously described, FDG uptake was significantly higher in the spinal cord and lower in the brain motor cortex, in ALS compared to controls. While psoas AAC was similar in patients and controls, in ALS a significant reduction in psoas volume (3.6 ± 1.02 vs 4.12 ± 1.33 mL/kg; p < 0.01) and increase in psoas N-SUV (0.45 ± 0.19 vs 0.29 ± 0.09; p < 0.001) were observed. Higher heterogeneity of psoas FDG uptake was also documented in ALS (VC-SUV 8 ± 4%, vs 5 ± 2%, respectively, p < 0.001) and significantly predicted overall survival at Kaplan-Meier analysis. VC-SUV prognostic power was confirmed by univariate analysis, while the multivariate Cox regression model identified the spinal cord metabolic activation as the only independent prognostic biomarker.

CONCLUSION

The present data suggest the existence of a common mechanism contributing to disease progression through the metabolic impairment of both second motor neuron and its effector.

Relationship Between Changes in Myocardial F-18 Fluorodeoxyglucose Uptake and Radiation Dose After Adjuvant Three-Dimensional Conformal Radiotherapy in Patients with Breast Cancer

This study aimed to assess the relationship between radiation dose and changes in the irradiated myocardial F-18 fluorodeoxyglucose (FDG) uptake after radiotherapy (RT) in breast cancer patients. The data of 55 patients with left and 48 patients with right breast cancer who underwent curative surgical resection and adjuvant three-dimensional conformal RT and staging (PET1), post-adjuvant chemotherapy (PET2), post-RT (PET3), and surveillance (PET4) FDG positron emission tomography/computed tomography (PET/CT) were retrospectively reviewed. The median interval between PET1 and curative surgical resection, between the end of adjuvant chemotherapy and PET2, between the end of RT and PET3, and between the end of RT and PET4 were five days, 13 days, 132 days, and 353 days, respectively. The myocardial-to-blood pool uptake ratio was measured in all patients. For patients with left breast cancer, the 30 Gy- (30 Gy) and 47.5 Gy-irradiated myocardium-to-low-irradiated myocardium (47.5 Gy) FDG uptake ratios were additionally measured. There were no differences in the myocardial-to-blood pool uptake ratios between left and right breast cancer on all PET scans. For left breast cancer, higher 30 Gy and 47.5 Gy uptake ratios were observed on PET3 than on PET1 and PET2. Both uptake ratios decreased on PET4 compared to PET3, but, were still higher compared to PET1. On PET3 and PET4, the 47.5 Gy were higher than the 30 Gy uptake ratios, while there were no differences between them on PET1 and PET2. Although the whole myocardium FDG uptake showed no significant change, the irradiated myocardium FDG uptake significantly increased after RT and was related to radiation dose to the myocardium in breast cancer patients. These results might be an imaging evidence that supports the increased risk of heart disease after RT in patients with left breast cancer.

Clinical implication of myocardial FDG uptake pattern in oncologic PET: retrospective comparison study with stress myocardial perfusion imaging as the reference standard

OBJECTIVE

The purpose of this study was to determine the clinical implication of the myocardial FDG uptake patterns by comparing with the results of stress myocardial perfusion imaging (MPI) as the reference standard.

METHODS

By reviewing the medical records, 86 pairs of stress MPI and FDG PET/CT of 84 patients who underwent stress MPI and oncologic FDG PET/CT in 1 month were included in this study. The patterns of the myocardial FDG uptake were classified into five patterns such as 'low', 'diffuse', 'basal ring', 'focal high', and 'focal defect on diffuse high'. MPI was evaluated using a 5-point scoring model ranging from 0 (normal uptake) to 4 (uptake absent) based on the 17-segment model. The summed stress score of 4 or higher was defined as 'abnormal MPI'. Factors predictive of abnormal MPI were analyzed using a log-rank multivariate test and p < 0.05 was set as significant.

RESULTS

Abnormal MPI was observed in only 16 of 36 (44%) patients with 'low' pattern, 10 of 23 (43%) patients with 'diffuse high' pattern, and 1 of 9 (11%) patients with 'basal ring' pattern, but in 8 of 9 (89%) patients with 'focal high' pattern, and 8 of 9 (89%) patients with 'focal defect on diffuse high' pattern. The log-rank multivariate test revealed that 'focal high' and 'focal defect on diffuse high' pattern were correlated with an abnormal MPI.

CONCLUSIONS

These results indicate that further cardiac work-up might be helpful in the patients with 'focal high' pattern or 'focal defect on diffuse high' pattern of myocardial FDG at oncologic PET. A prospective study should be needed to further support this conclusion.

Advanced Imaging Modalities to Monitor for Cardiotoxicity

Early detection and treatment of cardiotoxicity from cancer therapies is key to preventing a rise in adverse cardiovascular outcomes in cancer patients. Over-diagnosis of cardiotoxicity in this context is however equally hazardous, leading to patients receiving suboptimal cancer treatment, thereby impacting cancer outcomes. Accurate screening therefore depends on the widespread availability of sensitive and reproducible biomarkers of cardiotoxicity, which can clearly discriminate early disease. Blood biomarkers are limited in cardiovascular disease and clinicians generally still use generic screening with ejection fraction, based on historical local expertise and resources. Recently, however, there has been growing recognition that simple measurement of left ventricular ejection fraction using 2D echocardiography may not be optimal for screening: diagnostic accuracy, reproducibility and feasibility are limited. Modern cancer therapies affect many myocardial pathways: inflammatory, fibrotic, metabolic, vascular and myocyte function, meaning that multiple biomarkers may be needed to track myocardial cardiotoxicity. Advanced imaging modalities including cardiovascular magnetic resonance (CMR), computed tomography (CT) and positron emission tomography (PET) add improved sensitivity and insights into the underlying pathophysiology, as well as the ability to screen for other cardiotoxicities including coronary artery, valve and pericardial diseases resulting from cancer treatment. Delivering screening for cardiotoxicity using advanced imaging modalities will however require a significant change in current clinical pathways, with incorporation of machine learning algorithms into imaging analysis fundamental to improving efficiency and precision. In the future, we should aspire to personalized rather than generic screening, based on a patient’s individual risk factors and the pathophysiological mechanisms of the cancer treatment they are receiving. We should aspire that progress in cardiooncology is able to track progress in oncology, and to ensure that the current ‘one size fits all’ approach to screening be obsolete in the very near future.

Evidence for a cardiac metabolic switch in patients with Hodgkin's lymphoma

AIMS

Our aim was to investigate the glucose uptake in cancer patients suffering from different entities, using ¹⁸ F-FDG positron emission tomography-computed tomography scans. We further aimed at identifying potential variables altering cardiac and skeletal muscle glucose metabolism.

METHODS AND RESULTS

In a retrospective cohort study, we analysed cardiac and skeletal muscle ¹⁸ F-FDG uptake in onco-positron emission tomography-computed tomography scans in adult patients suffering from Hodgkin's lymphoma, non-Hodgkin's lymphoma, and non-lymphatic cancer including patients suffering from thyroid cancer, bronchial carcinoma, and malignant melanoma. Univariate logistic regression models were created for increased cardiac and skeletal muscle ¹⁸ F-FDG uptake using cancer entity, sex, age, previous radiation, previous chemotherapy, diabetes, obesity, serum glucose levels, renal function, and thyroid function as parameters. Multivariate models were created by selecting variables according to Akaike's information criterion in a step-down approach. Between 2014 and 2018, a total of 337 consecutive patients suffering from Hodgkin's lymphoma (n = 52), non-Hodgkin's lymphoma (n = 57), and non-lymphatic cancer (n = 228) were included in the analysis. Univariate logistic regression models showed high serum glucose levels to be associated with lower absorption rates in both cardiac and skeletal muscle (odds ratio [OR] 0.38 [0.23, 0.60, 95% confidence interval-CI], P < 0.0001, and 0.52 [0.33, 0.82, 95% CI], P < 0.005, respectively). Hodgkin's lymphoma was associated with an increase in cardiac uptake (OR 2.4 [1.3, 4.5, 95% CI], P < 0.005). Decreased skeletal muscle ¹⁸ F-FDG uptake was noted in elderly and obese patients. In our multivariate analysis, Hodgkin's lymphoma patients showed higher cardiac ¹⁸ F-FDG uptake, while non-Hodgkin's lymphoma patients did not differ significantly from non-lymphatic cancer patients (OR 1.6 [0.7, 3.3, 95% CI], P = 0.24). High serum glucose levels and prior chemotherapy were both associated with a significantly decreased cardiac ¹⁸ F-FDG uptake (OR 0.40 [0.24, 0.65, 95% CI], P < 0.0005, and 0.50 [0.27, 0.90, 95% CI], P < 0.05, respectively). Notably, prior chemotherapy did not influence FDG uptake in skeletal muscle to the same extent. Obesity and older age were both significantly associated with decreased gluteal ¹⁸ F-FDG uptake (OR 0.49 [0.27, 0.89, 95% CI], P < 0.05, and 0.47 [0.25, 0.87, 95% CI], P < 0.05).

CONCLUSIONS

Our data provide evidence for metabolic alterations in patients with Hodgkin's lymphoma related to cardiac glucose uptake in humans. This effect was independent from skeletal muscle metabolism.

Cardiovascular imaging in cardio-oncology

Cancer therapy may lead to cardiovascular complications and can promote each aspect of cardiac disease manifestation, such as vascular disease including coronary heart disease, myocardial diseases including heart failure, structural heart diseases including valvular heart diseases, and rhythm disorders. All potential complications of cancer therapy onto the cardiovascular system require imaging for diagnostic workup as well as monitoring of therapy. Transthoracic echocardiography (TTE) is the most frequently used tool for assessment of cardiac function during or after cancer therapy in daily clinical routine. With modern techniques like strain analysis, echocardiography allows to detect a variety of cardiac diseases as caused by cancer therapy even at subclinical stages. For further workup, specific imaging techniques including nuclear imaging are needed in a multimodality imaging approach to in detail characterize the underlying pathophysiology and to improve the management of the patients. Therefore, the field of imaging in cardio-oncology is rapidly growing. This review article will give an overview about existing literature regarding the role of imaging in the diagnostic evaluation and management of therapy in patient with prior or ongoing cancer therapy.

An increase in myocardial 18-fluorodeoxyglucose uptake is associated with left ventricular ejection fraction decline in Hodgkin lymphoma patients treated with anthracycline

Background

Doxorubicin (DOX)-based chemotherapy for Hodgkin lymphoma (HL) yields excellent disease-free survival, but poses a substantial risk of subsequent left ventricular (LV) dysfunction and heart failure, typically with delayed onset. At the cellular level, this cardiotoxicity includes deranged cardiac glucose metabolism.

Methods

By reviewing the hospital records from January 2008 through December 2016, we selected HL patients meeting the following criteria: ≥ 18 year-old; first-line DOX-containing chemotherapy; no diabetes and apparent cardiovascular disease; 18-fluoro-deoxyglucose positron emission tomography (¹⁸FDG-PET) scans before treatment (PET^STAGING), after 2 cycles (PET^INTERIM) and at the end of treatment (PET^EOT); at least one echocardiography ≥ 6 months after chemotherapy completion (ECHO^POST). We then evaluated the changes in LV ¹⁸FDG standardized uptake values (SUV) during the course of DOX therapy, and the relationship between LV-SUV and LV ejection fraction (LVEF), as calculated from the LV diameters in the echocardiography reports with the Teicholz formula.

Results

Forty-three patients (35 ± 13 year-old, 58% males) were included in the study, with 26 (60%) also having a baseline echocardiography available (ECHO^PRE). LV-SUV gradually increased from PET^STAGING (log-transformed mean 0.20 ± 0.27) to PET^INTERIM (0.27 ± 0.35) to PET^EOT (0.30 ± 0.41; P for trend < 0.001). ECHO^POST was performed 22 ± 17 months after DOX chemotherapy. Mean LVEF was normal (68.8 ± 10.3%) and only three subjects (7%) faced a drop below the upper normal limit of 53%. However, when patients were categorized by median LV-SUV, LVEF at ECHO^POST resulted significantly lower in those with LV-SUV above than below the median value at both PET^INTERIM (65.5 ± 11.8% vs. 71.9 ± 7.8%, P = 0.04) and PET^EOT (65.6 ± 12.2% vs. 72.2 ± 7.0%, P = 0.04). This was also the case when only patients with ECHO^PRE and ECHO^POST were considered (LVEF at ECHO^POST 64.7 ± 8.9% vs. 73.4 ± 7.6%, P = 0.01 and 64.6 ± 9.3% vs. 73.5 ± 7.0%, P = 0.01 for those with LV-SUV above vs. below the median at PET^INTERIM and PET^EOT, respectively). Furthermore, the difference between LVEF at ECHO^PRE and ECHO^POST was inversely correlated with LV-SUV at PET^EOT (P < 0.01, R² = − 0.30).

Conclusions

DOX-containing chemotherapy causes an increase in cardiac ¹⁸FDG uptake, which is associated with a decline in LVEF. Future studies are warranted to understand the molecular basis and the potential clinical implications of this observation.

A Score-Based Approach to 18F-FDG PET Images as a Tool to Describe Metabolic Predictors of Myocardial Doxorubicin Susceptibility

Purpose: To verify the capability of ¹⁸F-fluorodeoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT) to identify patients at higher risk of developing doxorubicin (DXR)-induced cardiotoxicity, using a score-based image approach. Methods: 36 patients underwent FDG-PET/CT. These patients had shown full remission after DXR-based chemotherapy for Hodgkin’s disease (DXR dose: 40–50 mg/m² per cycle), and were retrospectively enrolled. Inclusion criteria implied the presence of both pre- and post-chemotherapy clinical evaluation encompassing electrocardiogram (ECG) and echocardiography. Myocardial metabolism at pre-therapy PET was evaluated according to both standardized uptake value (SUV)- and score-based approaches. The capability of the score-based image assessment to predict the occurrence of cardiac toxicity with respect to SUV measurement was then evaluated. Results: In contrast to the SUV-based approach, the five-point scale method does not linearly stratify the risk of the subsequent development of cardiotoxicity. However, converting the five-points scale to a dichotomic evaluation (low vs. high myocardial metabolism), FDG-PET/CT showed high diagnostic accuracy in the prediction of cardiac toxicity (specificity = 100% and sensitivity = 83.3%). In patients showing high myocardial uptake at baseline, in which the score-based method is not able to definitively exclude the occurrence of cardiac toxicity, myocardial SUV mean quantification is able to further stratify the risk between low and intermediate risk classes. Conclusions: the score-based approach to FDG-PET/CT images is a feasible method for predicting DXR-induced cardiotoxicity. This method might improve the inter-reader and inter-scanner variability, thus allowing the evaluation of FDG-PET/CT images in a multicentral setting.