Diagnostic test accuracies of F-18 FDG PET for characterisation of cardiac masses compared to conventional imaging techniques: systematic review and meta-analysis

OBJECTIVE

The present systematic review and meta-analysis compared the diagnostic performance of F-18 fludeoxyglucose positron emission tomography (18F-FDG PET) and conventional imaging, including MRI, echocardiography, and CT, in characterising cardiac masses.

METHODS

A literature search of the PubMed, Cochrane, and EMBASE databases for studies comparing the diagnostic accuracies of 18F-FDG PET and conventional imaging in characterising cardiac masses, from inception of indexing to 31 July 2020, was performed. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess study quality. Sensitivity and specificity across the studies were determined, positive and negative likelihood ratios (LR+ and LR-, respectively) were calculated, and summary receiver operating characteristic curves were constructed.

RESULTS

Of six included studies (n = 212 patients), 18F-FDG PET demonstrated a pooled sensitivity of 0.89 (95% confidence interval [CI] 0.81-0.94) and a pooled specificity of 0.89 (95% CI 0.80-0.94). LR syntheses yielded an overall LR+ of 7.9 (95% CI 4.3-14.6) and LR- of 0.12 (95% CI 0.07-0.22). The calculated pooled diagnostic odds ratio (DOR) was 64 (95% CI 23-181). For conventional imaging, the pooled sensitivity was 0.70 (95% CI 0.57-0.81) and the pooled specificity was 0.96 (95% CI 0.88-0.98). LR syntheses yielded an overall LR+ of 16.1 (95% CI 5.8-44.5) and LR- of 0.31 (95% CI 0.21-0.46). The evaluated pooled DOR was 52 (95% CI 17-155).

CONCLUSION

18F-FDG PET and conventional imaging demonstrated comparable diagnostic accuracies for the characterisation of cardiac masses. Further large multicentre studies are, however, required to corroborate the diagnostic performances of 18F-FDG PET and conventional imaging for the characterisation of cardiac masses.

ADVANCES IN KNOWLEDGE

No previous studies have comprehensively analysed the diagnostic performance of 18F-FDG PET/CT compared with conventional imaging techniques including echocardiography, CT, and MRI. According to the current study, 18F-FDG PET/CT yielded a pooled DOR of 64, whereas other conventional imaging techniques demonstrated a DOR of 52. As such, 18F-FDG PET/CT demonstrated sensitivity and specificity, with a high pooled DOR comparable with other conventional imaging modalities.

Diagnostic Accuracy of Cardiac Computed Tomography and 18-F Fluorodeoxyglucose Positron Emission Tomography in Cardiac Masses

OBJECTIVES

This study sought to assess the diagnostic accuracy of cardiac computed tomography (CT) and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) with positron emission tomography/computed tomography (PET/CT) in defining the nature of cardiac masses.

BACKGROUND

The diagnostic accuracy of cardiac CT and ¹⁸F-FDG PET/CT in identifying the nature of cardiac masses has been analyzed to date only in small samples.

METHODS

Of 223 patients with echocardiographically diagnosed cardiac masses, a cohort of 60 cases who underwent cardiac CT and ¹⁸F-FDG PET/CT was selected. All masses had histological confirmation, except for a minority of thrombotic formations. For each mass, 8 morphological CT signs, standardized uptake value (SUV_max, SUV_mean), metabolic tumor volume, and total lesion glycolysis in ¹⁸F-FDG PET were used as diagnostic markers.

RESULTS

Irregular tumor margins, pericardial effusion, invasion, solid nature, mass diameter, CT contrast uptake, and pre-contrast characteristics were strongly associated with the malignant nature of masses. The coexistence of at least 5 CT signs perfectly identified malignant masses, whereas the detection of 3 or 4 CT signs did not accurately discriminate the masses' nature. The mean SUV_max, SUV_mean, metabolic tumor volume, and total lesion glycolysis values were significantly higher in malignant than in benign masses. The diagnostic accuracy of SUV, metabolic tumor volume, and total lesion glycolysis ¹⁸F-FDG PET/CT parameters was excellent in detecting malignant masses. Among patients with 3 or 4 pathological CT signs, the presence of at least 1 abnormal ¹⁸F-FDG PET/CT parameter significantly increased the identification of malignancies.

CONCLUSIONS

Cardiac CT is a powerful tool to diagnose cardiac masses as the number of abnormal signs was found to correlate with the lesions' nature. Similarly, ¹⁸F-FDG PET/CT accurately identified malignant masses and contributed with additional valuable information in diagnostic uncertainties after cardiac CT. These imaging tools should be performed in specific clinical settings such as involvement of great vessels or for disease-staging purposes.