Evaluation of ^sup 18^F-FDG PET/CT in the diagnosis of cardiac lymphoma

Purpose: To evaluate the ability of (18)F-fluorodeoxyglucose (FDG) imaging for the detection of cardiac lymphoma (CL) which contains heart involvement and pericardium involvement. Methods: Our series comprised 27 patients with CL whom received 18F-FDG imaging from 2114 patients with lymphoma confirmed by pathology. We described the characteristic findings in each imaging and its clinical significance of CL. Results: For all these 27 patients, 33% (9/27 cases) had heart involvement with SUVmax 13.9±4.9 (range 8.3 to 22.5), and 63% (5/8 cases) of them showed abnormal cardiac morphology by CT. All of these 8 cases had right atrium (RA) involvement, 4 cases involved right ventricle (RV), 3 cases involved left atrium (LA), 2 case involved left ventricle (LV). There were 78% (21/27 cases) had pericardium involvement with SUVmax 7.9±5.2 (range 1.7 to 25.2). There were 78% (21/27 cases) patients had pericardium involvement, 57% (12/21 cases) of them had only one mass in pericardium and 43% (9/21 cases) had more than one mass in pericardium, 24% (5/21 cases) had huge mediastinal mass that invasion pericardium,.67% (14/21 cases) of them showed local thickening of pericardium by CT scan. 59% (16/27 cases) patients had pericardial effusion with the depth 1.5±0.9cm (range, 0.5cm to 3.7cm). The depth of pericardial effusion had no correlation with the location of tumor (P=1.000, rs=-0.000), the tumor SUVmax (P=0.293, r=0.254), and the tumor size (P=0.599, r=-0.129). There were 18 B-cell lymphoma, 6 T-cell lymphoma, and 3 Hodgkin lymphoma. Heart seemed to be more often involved in the case of B-cell lymphoma than T-cell and Hodgkin lymphoma (44% vs. 17% and 0%),while pericardium was more often infiltrated in patients with T-cell and Hodgkin lymphoma than B-cell lymphoma (100% and 100% vs. 67%), and Hodgkin lymphoma was more likely to have pericardial effusion than non-Hodgkin lymphoma (100% vs. 54%), but there had no statistical difference between any two groups. Conclusion: CL is an FDG-avid tumor consistent with extracardiac lesions. 18F-FDG PET/CT is an effective modality allowed earlier detection of cardiac lymphoma as well as more accurate diagnosis and characterization.