18F-FDG PET/CT in diagnostic and prognostic evaluation of patients with cardiac masses: a retrospective study.

Abstract

Correct diagnosis and prognostic assessment of cardiac masses are crucial before therapy. We evaluated the diagnostic and prognostic value of 18F-FDG PET/CT in patients with cardiac masses. 18F-FDG PET/CT images of 64 patients with 65 cardiac masses were retrospectively analysed (34 men, 30 women; average age, 51.2 ± 17.5years). Comparisons of CT features and 18F-FDG metabolic indices between benign and malignant entities, as well as among primary and secondary malignancies and lymphoma, were performed. The diagnostic values of PET/CT for distinguishing benign versus malignant masses were calculated. PET/CT data were further assessed for the predictive value for overall survival (OS) using the Cox proportional hazards model to assess potential independent predictors. Kaplan-Meier curves were generated to assess the value of PET/CT for prognostication. Statistically significant differences in various morphological features and metabolic indices between benign and malignant masses were found. An SUVmax of 6.75 was the optimal cutoff value to differentiate between benign and malignant masses, and the diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 92.11%, 88.89%, 90.77%, 92.11%, and 88.89%, respectively. Taking CT features and SUVmax ≥ 6.75 as a criterion, the values were 76.32%, 100.00%, 86.15%, 100.00%, and 75.00%, respectively; taking ≥ 3 CT features or SUVmax ≥ 6.75 as a criterion, the values were 94.74%, 88.89%, 92.31%, 92.31%, and 92.31%, respectively, indicating optimal diagnostic performance when paired with the anatomic information provided by the CT component. A univariate analysis of OS determined that surrounding tissue infiltration, epicardial infiltration, necrosis, multiple chambers or vessel involvement, distant metastasis, SUVmax, SUVmean, metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were significant predictors of survival. In the multivariate analysis, only SUVmax ≥ 6.715 was significant (P < 0.01). Median OS was 1460days for SUVmax < 6.715 and 342days for SUVmax ≥ 6.715 (P < 0.01). 18F-FDG PET/CT is helpful in the diagnosis of cardiac masses before treatment and has value in detecting extracardiac primary or secondary tumours. 18F-FDG PET/CT could also be a promising tool to provide prognostic information for these patients, especially SUVmax displaying independent prognostic value.