Diagnostic challenges in primary cardiac lymphoma, the opportunity of ¹⁸F-FDG PET/CT integrated with contrast-enhanced CT

Background: The purpose of this study was to retrospectively evaluate the value of ¹⁸F-FDG PET/CT integrated with contrast-enhanced CT (CECT) in the differential diagnosis of primary cardiac lymphomas (PCLs) and primary cardiac angiosarcomas (PCAs).

Methods: Clinical and imaging data of patients with PCLs and PCAs were collected. All patients underwent preoperative ¹⁸F-FDG PET/CT and thoracic CECT. The enhancement pattern and tumor morphology were analyzed using CECT images. The intensity- and volume-based PET parameters of cardiac lesions were analyzed. The performance characteristics of all parameters were assessed.

Results: Nine patients with PCL and eight patients with PCA were analyzed. There were significant differences in SUVmax (t = 3.790, P = .002), SUVmean (t = 4.273, P = .001), metabolic tumor volume (U = 13.00, P = .027), tumor-to-liver ratio (U = 10.00, P = .011), and total lesion glycolysis (U = 4.0, P = .001) between PCLs and PC¹⁸As. There were significant differences in the enhancement pattern of tumors (P = .002) and tumor morphology (P = .015). The combination of F-FDG PET/CT and CECT improved the diagnostic accuracy, and the combination cutoff (SUVmean > 5.17) could reach 100%, but the difference was not statistically significant (P > .05).

Conclusion: The intensity- and volume-based PET parameters of PCL were significantly higher than those of PCA. The enhancement pattern and tumor morphology were also different. According to these characteristics, the two most common types of primary cardiac malignancies can be differentiated.