Clinical relevance of radionuclide angiography and antimyosin immunoscintigraphy for risk assessment in epirubicin cardiotoxicity

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.

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.

Transduction catalysis: Doxorubicin amplifies rAAV-mediated gene expression in the cortex of higher-order vertebrates

Rapid and efficient gene transduction via recombinant adeno-associated viruses (rAAVs) is highly desirable across many basic and clinical research domains. Here, we report that vector co-infusion with doxorubicin, a clinical anti-cancer drug, markedly enhanced rAAV-mediated transgene expression in the cerebral cortex across mammalian species (cat, mouse, and macaque), acting throughout the time period examined and detectable at just three days after transfection. This enhancement showed serotype generality, being common to all rAAV serotypes tested (2, 8, 9, and PHP.eB) and was observed both locally and at remote locations consistent with doxorubicin undergoing retrograde axonal transport. All these effects were observed at doses matching human blood plasma levels in clinical therapy and lacked detectable cytotoxicity as assessed by cell morphology, activity, apoptosis, and behavioral testing. Altogether, this study identifies an effective means to improve the capability and scope of in vivo rAAV applications, amplifying cell transduction at doxorubicin concentrations paralleling medical practice.

From Molecular Mechanisms to Clinical Management of Antineoplastic Drug-Induced Cardiovascular Toxicity: A Translational Overview

Significance: Antineoplastic therapies have significantly improved the prognosis of oncology patients. However, these treatments can bring to a higher incidence of side-effects, including the worrying cardiovascular toxicity (CTX). Recent Advances: Substantial evidence indicates multiple mechanisms of CTX, with redox mechanisms playing a key role. Recent data singled out mitochondria as key targets for antineoplastic drug-induced CTX; understanding the underlying mechanisms is, therefore, crucial for effective cardioprotection, without compromising the efficacy of anti-cancer treatments. Critical Issues: CTX can occur within a few days or many years after treatment. Type I CTX is associated with irreversible cardiac cell injury, and it is typically caused by anthracyclines and traditional chemotherapeutics. Type II CTX is generally caused by novel biologics and more targeted drugs, and it is associated with reversible myocardial dysfunction. Therefore, patients undergoing anti-cancer treatments should be closely monitored, and patients at risk of CTX should be identified before beginning treatment to reduce CTX-related morbidity. Future Directions: Genetic profiling of clinical risk factors and an integrated approach using molecular, imaging, and clinical data may allow the recognition of patients who are at a high risk of developing chemotherapy-related CTX, and it may suggest methodologies to limit damage in a wider range of patients. The involvement of redox mechanisms in cancer biology and anticancer treatments is a very active field of research. Further investigations will be necessary to uncover the hallmarks of cancer from a redox perspective and to develop more efficacious antineoplastic therapies that also spare the cardiovascular system.

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.

Recent Advances on Pathophysiology, Diagnostic and Therapeutic Insights in Cardiac Dysfunction Induced by Antineoplastic Drugs

Along with the improvement of survival after cancer, cardiotoxicity due to antineoplastic treatments has emerged as a clinically relevant problem. Potential cardiovascular toxicities due to anticancer agents include QT prolongation and arrhythmias, myocardial ischemia and infarction, hypertension and/or thromboembolism, left ventricular (LV) dysfunction, and heart failure (HF). The latter is variable in severity, may be reversible or irreversible, and can occur soon after or as a delayed consequence of anticancer treatments. In the last decade recent advances have emerged in clinical and pathophysiological aspects of LV dysfunction induced by the most widely used anticancer drugs. In particular, early, sensitive markers of cardiac dysfunction that can predict this form of cardiomyopathy before ejection fraction (EF) is reduced are becoming increasingly important, along with novel therapeutic and cardioprotective strategies, in the attempt of protecting cardiooncologic patients from the development of congestive heart failure.

Cardiotoxicity of antineoplastic agents: what is the present and future role for imaging?

As antineoplastic treatment options expand at an increasing rate, both traditional and novel agents continue to be limited by their cardiotoxic effects. While functional decline becomes clinically apparent at late states of toxicity, little is known about early stages during which treatment or prevention may still be an option. Several imaging modalities,including echocardiography, multiple gated acquisition, and cardiac magnetic resonance imaging have the ability to identify cardiac effects before they produce clinical symptoms.Here we discuss the current and future role of cardiac imaging in the assessment of cardiotoxicity of antineoplastic agents. effects on cardiac tissue, resulting in myocardial cellular damage,and ultimately lead to a wide range of effects including electrophysiological abnormalities, symptomatic heart failure(HF), and even death. This represents a limiting factor in the therapy of several otherwise treatable neoplasms [2].The cardiotoxicity of antineoplastic agents raises several important questions regarding the actual prevalence of cardiac toxicity, the ability to effectively treat or prevent such effects with pharmaceutical interventions, and the availability of a means for early diagnosis. Here, we focus on the latter, specifically examining current and potential future imaging strategies to detect the cardiac effects of chemotherapeutic agents.

Noninvasive imaging of cardiovascular injury related to the treatment of cancer

The introduction of multiple treatments for cancer, including chemotherapeutic agents and radiation therapy, has significantly reduced cancer-related morbidity and mortality. However, these therapies can promote a variety of toxicities, among the most severe being the ones involving the cardiovascular system. Currently, for many surviving cancer patients, cardiovascular (CV) events represent the primary cause of morbidity and mortality. Recent data suggest that CV injury occurs early during cancer treatment, creating a substrate for subsequent cardiovascular events. Researchers have investigated the utility of noninvasive imaging strategies to detect the presence of CV injury during and after completion of cancer treatment because it starts early during cancer therapy, often preceding the development of chemotherapy or cancer therapeutics related cardiac dysfunction. In this State-of-the-Art Paper, we review the utility of current clinical and investigative CV noninvasive modalities for the identification and characterization of cancer treatment-related CV toxicity.

Non-pegylated liposomal Doxorubicin-cyclophosphamide in sequential regimens with taxanes as neoadjuvant chemotherapy in breast cancer patients

PURPOSE

Chemotherapy regimens containing anthracyclines and taxanes represent the landmark of neoadjuvant systemic therapy of breast cancer. In advanced breast cancer patients liposomal anthracyclines (LA) have shown similar efficacy and less cardiac toxicity when compared to conventional anthracyclines. We performed this retrospective analysis in order to evaluate the efficacy and tolerability of neoadjuvant regimens including LA outside of clinical trials in routine clinical practice.

METHODS

Fifty operable or locally advanced, HER2 negative, breast cancer patients were retrospectively identified in 5 Italian cancer centres. Nineteen patients had received 4 cycles of non-pegylated liposomal doxorubicin (NPLD) and cyclophosphamide, followed by 4 cycles of docetaxel, every 3 weeks. In 25 patients the reverse sequence was employed, and a third subgroup of 6 patients received 4 cycles of NPLD/cyclophosphamide every 3 weeks followed by 4 cycles of weekly carboplatin and paclitaxel.

RESULTS

We observed 10 pathological complete responses (pCR) (20.0%, 95%CI, 9% to 31%), and 35 (70%, 95%CI, 57.3% to 82.7%) partial responses (pPR), whereas no patients progressed onto therapy. In the small subset of triple negative tumors the pCR rate was 37.5%, and in tumors expressing ER and/or PgR it was 16.7%. A pCR rate of 26.5% was observed in tumors with high Ki-67, whereas in tumors with low Ki-67 only one (6.2%) pCR was observed (p=0.14). Treatments were well tolerated. The most common toxicities were myelosuppression and palmar-plantar erytrodysesthesia; 4 asymptomatic and transient LVEF decrease have been recorded, without any case of clinical cardiotoxicity.

CONCLUSIONS

NPLD-cyclophosphamide and taxanes sequential regimens were proven effective and well tolerated in breast cancer patients with contra-indication to conventional anthracyclines undergoing neoadjuvant chemotherapy, even outside of clinical trials in everyday clinical practice.

Scintigraphic techniques for early detection of cancer treatment-induced cardiotoxicity

New antitumor agents have resulted in significant survival benefits for cancer patients. However, several agents may have serious cardiovascular side effects. Left ventricular ejection fraction measurement by (99m)Tc multigated radionuclide angiography is regarded as the gold standard to measure cardiotoxicity in adult patients. It identifies left ventricular dysfunction with high reproducibility and low interobserver variability. A decrease in left ventricular ejection fraction, however, is a relatively late manifestation of myocardial damage. Nuclear cardiologic techniques that visualize pathophysiologic processes at the tissue level could detect myocardial injury at an earlier stage. These techniques may give the opportunity for timely intervention to prevent further damage and could provide insights into the mechanisms and pathophysiology of cardiotoxicity caused by anticancer agents. This review provides an overview of past, current, and promising newly developed radiopharmaceuticals and describes the role and recent advances of scintigraphic techniques to measure cardiotoxicity. Both first-order functional imaging techniques (visualizing mechanical [pump] function), such as (99m)Tc multigated radionuclide angiography and (99m)Tc gated blood-pool SPECT, and third-order functional imaging techniques (visualizing pathophysiologic and neurophysiologic processes at the tissue level) are discussed. Third-order functional imaging techniques comprise (123)I-metaiodobenzylguanidine scintigraphy, which images the efferent sympathetic nervous innervations; sympathetic neuronal PET, with its wide range of tracers; (111)In-antimyosin, which is a specific marker for myocardial cell injury and necrosis; (99m)Tc-annexin V scintigraphy, which visualizes apoptosis and cell death; fatty-acid-use scintigraphy, which visualizes the storage of free fatty acids in the lipid pool of the cytosol (which can be impaired by cardiotoxic agents); and (111)In-trastuzumab imaging, to study trastuzumab targeting to the myocardium. To define the prognostic importance and clinical value of each of these functional imaging techniques, prospective clinical trials are warranted.

Doxorubicin augments rAAV-2 transduction in rat neuronal cells

Doxorubicin, an approved drug for cancer therapy, was recently found to be a potent agent to augment adeno-associated virus (AAV)-mediated transgene expression, especially in airway cells. Recombinant AAV type 2 (rAAV-2) has been shown to preferentially transduce neural tissues and is considered as the primary viral vector for the treatments of various neurodegenerative diseases including Parkinson's disease (PD). The goal of this study is to investigate whether doxorubicin can be applied to increase the efficacy of rAAV-2 transduction in the central nervous system. We co-administrated doxorubicin with AV2.luc/EGFP into the rat striatum, a preferred target site for PD gene therapy, and found that doxorubicin augmented rAAV-2 transduction dramatically without significant cytotoxicity and alteration of rAAV-2 tropism. By evaluating the effects of doxorubicin on rAAV-2 transduction in PC12 and MN9D neuronal cells, we found that doxorubicin appeared to promote the nuclear accumulation of rAAV-2, but did not affect viral binding or uptake. Our data suggested that doxorubicin might play an important role in modulating rAAV-2 intracellular trafficking in neuron-like cells. Our study also provided the initial in vivo evidence to facilitate AAV-mediated gene expression in the midbrain with the treatment of doxorubicin.

Cardiac toxicity in breast cancer survivors: review of potential cardiac problems

As breast cancer survival is increased by the diagnosis of earlier-stage disease and treatments improve, the side effects of cancer treatments, such as cardiotoxicity, remain clinically important. Although physicians have known for 30 years that anthracyclines cause acute and chronic cardiotoxicity, the cardiotoxic effects of radiation therapy, hormonal therapy (including tamoxifen and the aromatase inhibitors), and chemotherapy with taxanes and trastuzumab treatment have emerged more recently. This review examines the cardiac toxicity of adjuvant therapy, monitoring for early changes and existing guidelines for monitoring cardiac function in patients with breast cancer.

Monitoring chemotherapy-induced cardiotoxicity: role of cardiac nuclear imaging

Cardiotoxicity may result from a range of chemotherapeutic agents. The prevalence of cardiotoxicity from certain cytotoxic agents is reported to be significantly high. In addition to serious side effects and increased long-lasting morbidity and mortality, dose limitation and suboptimal usage is an important adverse effect. Nuclear cardiac imaging has played a quintessential and important role in identifying patients at risk and in the prevention and reduction of cardiac injury resulting from cytotoxic agents. Despite exploring a number of other diagnostic imaging or biochemical tools for identification of cardiac injury, nuclear cardiac imaging in the form of radionuclide angiocardiography continues to be the most suitable and cost-effective tool for reducing the prevalence of cases of cardiac dysfunction resulting from chemotherapy. This article reviews the prevalence, mechanisms, and prevention strategies for cardiotoxicity associated with some of the commonly known cytotoxic agents and the role of nuclear cardiac imaging in its monitoring and prevention, along with recent advances in this area.

Monitoring Cardiac Function in Patients Receiving Doxorubicin

Despite its well-known cardiotoxicity, doxorubicin continues to be an effective and widely used antineoplastic agent. Many efforts have focused on understanding the mechanism of doxorubicin-induced cardiotoxicity and on preventing it completely. Currently protective agents, eg, liposomal doxorubicin formulation, which results in less myocardial uptake, and the use of dexrazoxane, an intracellular iron chelator reducing the formation of radical complexes, have shown evidence of reducing incidences of cardiotoxicity at high dose of doxorubicin. However, they have not been able to completely eliminate cardiotoxicity. Therefore, it is crucial that careful monitoring to identify those patients who are at risk of developing unpredictable and sometimes-irreversible cardiac dysfunction is conducted while allowing other patients who respond to doxorubicin-containing therapy to receive their maximal therapeutic dose. Serial measurement of left ventricular ejection fraction by radionuclide angiocardiography remains a useful and widely adopted modality in monitoring patients that are receiving doxorubicin. Efforts are continuing on finding a more sensitive and reliable predictor of eventual clinical cardiac dysfunction.

High sensitivity of radiolabelled antimyosin scintigraphy in assessing anthracycline related early myocyte damage preceding cardiac dysfunction

In antimyosin scintigraphy was evaluated at various cumulative anthracycline dose levels in order to early identify patients with severe cardiac injury and increased long-term risk of cardiac dysfunction. Twenty-four patients receiving standard doses of 60-75 mg.m(-2) doxorubicin or 90-112.5 mg.m(-2) epirubicin were followed at baseline, low (two cycles), middle (four cycles), and high (six cycles) cumulative dose using (111)In antimyosin 48 h heart-to-lung ratio (HLR), left ventricle ejection fraction (LVEF) and peak filling rate (PFR). At a low cumulative dose only HLR was significantly increased (P=0.0001); at middle dose HLR (P<0.0001) and LVEF (P=0.0054), but not PFR, were significantly changed, and at high dose HLR (P<0.0001), LVEF (P=0.0001) and PFR (P=0.033) all changed significantly. Concerning individual results, HLR became abnormal in 18 patients (75%) at low, 22 (92%) at middle, and 24 (100%) at high cumulative dose whereas LVEF and PFR remained within normal limits in all patients. It is concluded that myocyte damage appears to precede left ventricle systolic and diastolic dysfunction in anthracycline treatment. (111)In antimyosin scintigraphy is very sensitive in detecting myocardial damage after cumulative dose levels even as low as 120-150 mg.m(-2) doxorubicin or 180-225 mg.m(-2) epirubicin.

Early decline in left ventricular ejection fraction predicts doxorubicin cardiotoxicity in lymphoma patients

Thirty adult patients with non-Hodgkin's lymphoma were studied to evaluate prospectively the significance of early decline in left ventricular ejection fraction after low cumulative doxorubicin dose (200 mg x m(-2)) in predicting the later impairment of left ventricular function. Cardiac function was monitored with radionuclide ventriculography at baseline and after cumulative doxorubicin doses of 200, 400 and 500 mg x m(-2). Cardiotoxicity was defined as a decrease in left ventricular ejection fraction of more than 10% units to a final left ventricular ejection fraction < or =50%. Twenty-eight patients received doxorubicin > or =400 mg x m(-2) and were evaluable for cardiotoxicity. Clinical heart failure developed in two patients (7%) after a cumulative doxorubicin dose of 500 mg m(-2). Left ventricular ejection fraction decreased more than 10% absolute ejection fraction units to a final left ventricular ejection fraction < or =50% in 10 patients (36%). Left ventricular ejection fraction decreased from 56+/-1.5% to 53.6+/-1.5% (P=0.016) in patients with no cardiotoxicity, and from 60.8+/-2.4% to 41.8+/-2.0% (P<0.001) in patients with cardiotoxicity. For patients who developed cardiotoxicity, the fall in left ventricular ejection fraction after a cumulative doxorubicin dose of only 200 mg x m(-2) was highly significant (left ventricular ejection fraction 49.7+/-1.8%, P=0.001 vs baseline). In receiver operator characteristic analysis, the area under the curve for the decrease in left ventricular ejection fraction at a cumulative doxorubicin dose of 200 mg x m(-2) for predicting cardiotoxicity in all patients was 0.858. The decrease in left ventricular ejection fraction of more than 4% units after a cumulative doxorubicin dose of 200 mg x m(-2) had a 90% sensitivity and 72% specificity for predicting later cardiotoxicity. Our results show that the significant impairment of left ventricular function during doxorubicin therapy can be predicted early, already at low cumulative doxorubicin doses. This finding may be of value in identifying patients at high or low risk for the development of anthracycline cardiotoxicity.

Anthracycline-induced cardiomyopathy: long-term effects on myocardial cell integrity, cardiac adrenergic innervation and fatty acid uptake

Cardiotoxicity of anthracyclines is a clinical challenge in cancer chemotherapy. Limited data is available on the physiological mechanisms responsible for anthracycline-induced heart failure or its recovery. We studied four patients with a history of severe anthracycline-induced heart failure manifested 2-116 months earlier by using radionuclide ventriculography for the measurement of left ventricular function, indium-111-antimyosin scintigraphy for the detection of myocardial cell injury and iodine-123-metaiodobenzylguanidine (MIBG) scintigraphy for the assessment of cardiac adrenergic innervation. Myocardial perfusion and fatty acid utilization were assessed with iodine-123-paraphenyl pentadecanoid acid (pPPA) and single photon emission computed tomography (SPECT). Symptoms of congestive heart failure (CHF) were still present in two patients whereas the others were asymptomatic at the time of the study. The patients who showed complete clinical recovery had normal or near normal left ventricular ejection fraction (LVEF) (47 and 52%), whereas the patients with symptoms of heart failure had low ejection fractions (21 and 31%). All patients presented with abnormal antimyosin uptake and decreased myocardial MIBG uptake. Patients with low ejection fraction tended to have higher antimyosin uptake suggesting more severe, persistent myocyte injury. All but one patient showed normal fatty acid utilization. These data suggest that patients with a history of severe anthracycline-induced cardiomyopathy have persistent myocardial cell injury and adrenergic dysfunction up to 10 years after the development of heart failure. These findings seem to be present regardless of recovery of left ventricular function.

Detection of doxorubicin cardiotoxicity by using iodine-123 BMIPP early dynamic SPECT: quantitative evaluation of early abnormality of fatty acid metabolism with the Rutland method

BACKGROUND

To evaluate the possibility of predicting the development of doxorubicin-induced cardiomyopathy, we performed quantitative assessment of the early kinetics of iodine-123 beta-methyl-iodophenyl-pentadecanoic acid (I-123 BMIPP) by means of dynamic myocardial SPECT.

METHODS

Thirty-six patients with various malignancies were examined. I-123 BMIPP dynamic myocardial SPECT was performed before chemotherapy, after chemotherapy, or both. Immediately after the injection of I-123 BMIPP (111 MBq), 30-second dynamic SPECT data were acquired successively for 15 minutes. The left ventricular (LV) myocardium was divided into 8 segments in short-axial and vertical slices. By using the time-activity curve (TAC) of each myocardial segment [Mo(t)] as an output function and the TAC of the LV cavity [B(t)] as an input function, the Rutland equation, Mo(t)/B(t)= F + K Integral of(B(t)dt/B(t)), was used as a means of assessing all segments.

RESULTS

Mo(t)/B(t) showed a good linear correlation with Integral of(B(t)dt/B(t)) from 30 seconds to 4 minutes in all 456 segments. The mean K value of 8 LV segments was significantly lower after chemotherapy than before chemotherapy (0.071+/-0.019 [n = 21] vs. 0.095+/-0.025 [n = 36], P<.001). In 21 patients in whom dynamic SPECT was performed both before and after chemotherapy, the mean K values of left ventricle showed a significant decrease, from 0.101+/-0.024 to 0.071 +/-0.019 (P<.0001). The fractional change in the value of K after chemotherapy showed a significant linear correlation with the administered dose of doxorubicin (r = 0.648, P<.002).

CONCLUSION

I-123 BMIPP dynamic myocardial SPECT may be clinically useful, because it permits the early detection of doxorubicin-induced cardiomyopathy.