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

Clinical Applications and Advancements of Positron Emission Tomography/Computed Tomography in Cardio-Oncology: A Comprehensive Literature Review and Emerging Perspectives

PURPOSE OF REVIEW

Recent advancements in molecular biology, biotechnology, chemistry/radiochemistry, artificial intelligence, and imaging techniques have significantly propelled the field of cardiovascular molecular imaging. This review aims to provide a comprehensive overview of the current state of cardiovascular positron emission tomography (PET) imaging and cardiac computed tomography (CT), exploring their roles in elucidating molecular and cellular processes, enabling early disease detection, and guiding novel therapeutic interventions for cardiovascular conditions.

RECENT FINDINGS

Cardiovascular PET imaging strives to uncover molecular and cellular events preceding visible anatomical manifestations or physiological changes. Meanwhile, cardiac CT has evolved into a multifaceted modality, offering insights into both anatomy and function. Utilizing advanced CT technologies allows for a thorough evaluation, encompassing fractional flow reserve, perfusion imaging, pericoronary adipose tissue attenuation, atherosclerotic plaque characterization, cardiomyopathies, structural cardiac abnormalities, and congenital heart anomalies. The emergence of hybrid imaging, combining PET and CT, presents innovative prospects in cardiology. This approach enables the simultaneous assessment of cardiac perfusion and coronary anatomy in a singular scan, providing complementary insights relevant to potential coronary artery disease. Despite the substantial potential impact, operational familiarity with this hybrid tool remains limited, and its integration into routine clinical practice warrants further exploration. In summary, the review underscores the transformative impact of recent technological advancements on cardiovascular molecular imaging. The integration of PET and CT, along with their individual capabilities, holds promise for early disease detection and informed clinical decision-making. While acknowledging the potential of hybrid imaging, it emphasizes the need for increased operational familiarity and continued exploration to facilitate its seamless integration into routine clinical practice. The insights gained from this review contribute to the ongoing dialogue in the field, offering a foundation for future research and advancements in cardiovascular imaging.

Cardioprotection strategies for anthracycline cardiotoxicity

Thanks to the fantastic progress in cancer therapy options, there is a growing population of cancer survivors. This success has resulted in a need to focus much effort into improving the quality of life of this population. Cancer and cardiovascular disease share many common risk factors and have an interplay between them, with one condition mechanistically affecting the other and vice versa. Furthermore, widely prescribed cancer therapies have known toxic effects in the cardiovascular system. Anthracyclines are the paradigm of efficacious cancer therapy widely prescribed with a strong cardiotoxic potential. While some cancer therapies cardiovascular toxicities are transient, others are irreversible. There is a growing need to develop cardioprotective therapies that, when used in conjunction with cancer therapies, can prevent cardiovascular toxicity and thus improve long-term quality of life in survivors. The field has three main challenges: (i) identification of the ultimate mechanisms leading to cardiotoxicity to (ii) identify specific therapeutic targets, and (iii) more sensible diagnostic tools to early identify these conditions. In this review we will focus on the cardioprotective strategies tested and under investigation. We will focus this article into anthracycline cardiotoxicity since it is still the agent most widely prescribed, the one with higher toxic effects on the heart, and the most widely studied.

Modern Instrumental Methods of Diagnostics and Risk Assessment of Developing Antitumor Therapy Cardiovasculotoxicity

The most important component of cardio-oncology is the assessment of the risk of development and diagnosis of cardiovascular toxicity of the antitumor therapy, the detection of which is largely based on visualization of the cardiovascular system. The article addresses up-to-date methods of non-invasive visualization of the heart and blood vessels, according to the 2022 European Society of Cardiology Clinical Guidelines on cardio-oncology. Also, the article discusses promising cardiovascular imaging techniques that are not yet included in the guidelines: assessment of coronary calcium using multislice computed tomography and positron emission computed tomography with 18F-labeled 2-deoxy-2-fluoro-d-glucose.

Early Detection of Cardiotoxicity Using [64Cu]Cu-NODAGA-E[(cRGDyK)]2 PET Imaging in a Rat Model of Doxorubicin-Induced Heart Failure

Doxorubicin (DOX) is a common and highly effective chemotherapeutic. However, its use is limited by cardiotoxic effects and the lack of methods to detect these at early time points. In the present study, we evaluated if [64Cu]Cu-NODAGA-E[(cRGDyK)]2 positron emission tomography-computed tomography ([64Cu]Cu-RGD PET/CT) could detect cardiotoxicity in a rat model of DOX-induced heart failure. Male Lewis rats were divided into two groups and treated with either a cumulative dose of 15 mg/kg of DOX or left untreated. Cardiac anatomy and function were assessed using magnetic resonance imaging at baseline and in week 8. [64Cu]Cu-RGD PET/CT scans were performed in week 4. DOX treatment led to a decline in pump function as well as an increase in cardiac and thymic uptake of [64Cu]Cu-RGD. In addition, DOX altered cardiac gene expression, led to infiltration of immune cells, reduced endothelial content, and increased interstitial fibrosis. Furthermore, concentrations of inflammatory plasma proteins were increased in the DOX group. In conclusion, DOX treatment resulted in the development of cardiotoxicity and heart failure, which could be detected using [64Cu]Cu-RGD PET/CT at early time points. [64Cu]Cu-RGD uptake in the myocardial septum and thymus predicted a low left ventricular ejection fraction in week 8.

Artificial intelligence-enhanced risk stratification of cancer therapeutics-related cardiac dysfunction using electrocardiographic images

Background

Risk stratification strategies for cancer therapeutics-related cardiac dysfunction (CTRCD) rely on serial monitoring by specialized imaging, limiting their scalability.

Objectives

To examine an artificial intelligence (AI)-enhanced electrocardiographic (AI-ECG) surrogate for imaging risk biomarkers, and its association with CTRCD.

Methods

Across a five-hospital U.S.-based health system (2013-2023), we identified patients with breast cancer or non-Hodgkin lymphoma (NHL) who received anthracyclines (AC) and/or trastuzumab (TZM), and a control cohort receiving immune checkpoint inhibitors (ICI). We deployed a validated AI model of left ventricular systolic dysfunction (LVSD) to ECG images (≥0.1, positive screen) and explored its association with i) global longitudinal strain (GLS) measured within 15 days (n=7,271 pairs); ii) future CTRCD (new cardiomyopathy, heart failure, or left ventricular ejection fraction [LVEF]<50%), and LVEF<40%. In the ICI cohort we correlated baseline AI-ECG-LVSD predictions with downstream myocarditis.

Results

Higher AI-ECG LVSD predictions were associated with worse GLS (-18% [IQR:-20 to -17%] for predictions<0.1, to -12% [IQR:-15 to -9%] for ≥0.5 (p<0.001)). In 1,308 patients receiving AC/TZM (age 59 [IQR:49-67] years, 999 [76.4%] women, 80 [IQR:42-115] follow-up months) a positive baseline AI-ECG LVSD screen was associated with ~2-fold and ~4.8-fold increase in the incidence of the composite CTRCD endpoint (adj.HR 2.22 [95%CI:1.63-3.02]), and LVEF<40% (adj.HR 4.76 [95%CI:2.62-8.66]), respectively. Among 2,056 patients receiving ICI (age 65 [IQR:57-73] years, 913 [44.4%] women, follow-up 63 [IQR:28-99] months) AI-ECG predictions were not associated with ICI myocarditis (adj.HR 1.36 [95%CI:0.47-3.93]).

Conclusion

AI applied to baseline ECG images can stratify the risk of CTRCD associated with anthracycline or trastuzumab exposure.

Physiological myocardial 18F-FDG uptake pattern in oncologic PET/CT: comparison with findings in cardiac sarcoidosis

Objectives

Physiological myocardial 18F-fluorodeoxyglucose (18F-FDG) uptake in oncologic positron emission tomography (PET)/computed tomography (CT) is commonly observed with multiple variations under clinical fasting conditions. The purpose of the present study was to evaluate physiological myocardial 18F-FDG uptake pattern by comparing with the results in cardiac sarcoidosis.

Methods

A total of 174 examinations in 174 patients without cardiac disease and 27 examinations in 17 patients with cardiac sarcoidosis were performed. The polar map images generated from 18F-FDG PET/CT data were visually assessed as "basal-ring," "focal," and "focal on diffuse" patterns. Semi-quantitative analysis was also performed using the regional relative 18F-FDG uptake (% uptake).

Results

On visual analysis, the "focal on diffuse" pattern was the most common in both examinations (43% and 59%, respectively). The physiological % uptake in the lateral and basal septal walls tended to be higher. Subgroup analysis showed significantly higher uptake in the mid-wall and left circumflex territory. In cardiac sarcoidosis patients, there was a significant difference only between segments 2 and 15 (p=0.04). No significant differences were observed between the base-mid-apical territory and coronary artery branch territory.

Conclusion

High 18F-FDG uptake in the basal septal walls is likely to be observed as both physiological uptake in patients without cardiac disease and pathological uptake in patients with cardiac sarcoidosis.

Anticancer Potential of Farnesol Against Human Osteosarcoma Saos-2 Cells and Human Colorectal Carcinoma HCT-116 Cells

INTRODUCTION

Increased colorectal carcinoma (CRC) and osteosarcoma prevalence, low survival rate, poor prognosis, and the limitations of existing anticancer therapies like side effects of drugs, non-specificity, short half-life, etc., pose a need for novel anticancer drugs. Farnesol, an organic sesquiterpene compound, found in the essential oils of various plants has been shown to possess antioxidant, anti-inflammatory, and anticancer properties. However, the anticancer effect of farnesol against CRC and osteosarcoma has not yet been adequately elucidated.

AIM

The aim of the study was to analyze the anticancer effects of farnesol against human osteosarcoma and CRC cell lines.

MATERIALS AND METHODS

Human osteosarcoma (Saos-2) and colorectal carcinoma (HCT-116) cell lines were procured and cultured at 37oC and 5% CO2. The cells were treated with 10, 20, 40, 60, 80, and 100 µM/ml and 20, 40, 60, 80, 100, and 120 µM/ml of farnesol for 24 hours, respectively. 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay was performed to assess the cytotoxicity of farnesol on Saos-2 and HCT-116 cells. Acridine orange/ethidium bromide staining was carried out to analyze apoptosis. 4',6-diamidino-2-phenylindole staining was done to observe the nuclear changes. Dichloro-dihydro-fluorescein diacetate staining was performed to assess the farnesol-induced reactive oxygen species (ROS)-mediated cell death.

RESULTS

Farnesol reduced the viability and proliferation of Saos-2 and HCT-116 cells in a dose-dependent manner. Farnesol was able to alter the cellular and nuclear morphology of Saos-2 and HCT-116 cells, promoting cell death. Farnesol-induced apoptosis in human osteosarcoma and colorectal carcinoma cell lines. Early apoptosis was observed in farnesol-treated HCT-116 cells. Additionally, ROS-mediated apoptotic cell death was reported in Saos-2 cells.

CONCLUSION

Farnesol has the potential to induce cytotoxicity against human osteosarcoma and CRC cell lines.