Differentiation of Malignant and Benign Cardiac Tumors Using ¹⁸F-FDG PET/CT

Abstract

In the diagnostic algorithm of cardiac tumors, the noninvasive determination of malignancy and metastatic spread is of major interest to stratify patients and to select and monitor therapies. In the diagnostic work-up, morphologic imaging modalities such as echocardiography or magnetic resonance tomography offer information on, for example, size, invasiveness, and vascularization. However, preoperative assessment of malignancy may be unsatisfactory. The aim of this study was to evaluate the diagnostic value of 18 F-FDG PET and the incremental diagnostic value of an optimized CT score in this clinical scenario. Methods: 18 F-FDG PET/CT scans (wholebody imaging with low-dose CT) of 24 consecutive patients with newly diagnosed cardiac tumors were analyzed (11 men, 13 women; mean age 6 SD, 59 6 13 y). The maximum standardized uptake values (SUV max ) of the tumors were measured. Patients were divided into 2 groups: benign cardiac tumors (n 5 7) and malignant cardiac tumors (n 5 17) (cardiac primaries [n 5 8] and metastases [n 5 9]). SUV max was compared between the 2 groups. Results were compared with contrast-enhanced CT, using standardized criteria of malignancy. Histology served as ground truth. Results: Mean SUV max was 2.8 6 0.6 in benign cardiac tumors and significantly higher both in malignant primary and in secondary cardiac tumors (8.0 6 2.1 and 10.8 6 4.9, P , 0.01). Malignancy was determined with a sensitivity of 100% and specificity of 86% (accuracy, 96%), after a cutoff with high sensitivity (SUV max of 3.5) was chosen to avoid false-negatives. Morphologic imaging reached a sensitivity of 82% and a specificity of 86% (accuracy, 83%). Both false-positive and false-negative decisions in morphology could be corrected in all but 1 case using a metabolic threshold with an SUV max of 3.5. In addition, extracardiac tumor manifestations were detected in 4 patients by whole-body 18 F-FDG PET/CT. Conclusion: 18 F-FDG PET/ CT can aid the noninvasive preoperative determination of malignancy and may be helpful in detecting metastases of malignant cardiac tumors.

A Patient with Lung Squamous Cell Carcinoma Presenting with Severe Cardiac Dysfunction Similar to Dilated Cardiomyopathy with Left Bundle Branch Block Induced by Myocardial Metastasis

“…Several recent reports demonstrate the utility of imaging studies such as cardiac MRI, CT and 18 Ffluorodeoxyglucose positron emission tomography / CT (FDG-PET/CT) to detect cardiac metastasis (11)(12)(13)(14). However, we were unable to perform any of these tests in the present case.…”

Cardiovascular Hybrid Imaging using PET/MRI

“…A single older case history of cardiac metastasis in a patient with squamous epithelial cancer of the lung demonstrates the use of post-hoc fused PET-MRI [29]. A study of the differentiation of benign and malignant cardiac tumors using FDG PET/CT showed high diagnostic accuracy (sensitivity 100 %, specificity 86 %) compared to the histopathological reference standard [30]. Due to the excellent morphological resolution of soft tissue processes of the heart in MRI and additional anatomical and functional tissue contrast through the use of special sequences, PET/MRI could yield additional improvement in the assessment of malignancy and local staging of local propagation of cardiac tumors.…”

Assessment of the myocardial FDG-PET image quality with the use of maximal Standardized Uptake Value myocardial to background index. Application of the results in regard to semiquantitative assessment of myocardial viability with cardiac dedicated softwar

“…Rahbar et al [7] analyzed SUVmax values in a group of 24 patients with myocardial tumors and found statistically significant differences between malignant and benign tumors (2.8 vs. 8.0, respectively). However, semiquantitative assessments of myocardial FDG accumulation should be treated with caution, considering the non-specific heterogeneous uptake with the wide range of physiological myocardial SUVmax values (even in a fasting state) and poorly estimated physiologic SUVmax range of the myocardium after a glucose load protocol.…”

“…An integrated PET/CT, where the functional scans are combined with CT is applied for many clinical purposes, including FDG myocardial viability assessment [5]. The possibility of the simultaneous analysis of perfusion or metabolism and morphological recognition of myocardial structures, such as coronary arteries, calcified plaques [6], myocardial tumors [7,8], or epicardial adipose tissue [9,10], allows for a more complete diagnosis. Additionally, the use of PET/CT allows for easy and accurate attenuation correction and semiquantitative calculation of glucose accumulation.…”