TY - JOUR T1 - <sup>18</sup>F-FDG PET/CT with Contrast-Enhanced CT Imaging Manifestations of Cardiac Lymphoma JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 488 LP - 488 VL - 61 IS - supplement 1 AU - Entao Liu AU - Taotao Sun AU - Siyun Wang AU - Haojian Dong AU - Zerui Chen AU - Shuxia Wang Y1 - 2020/05/01 UR - http://jnm.snmjournals.org/content/61/supplement_1/488.abstract N2 - 488Background: Cardiac lymphoma is very rare. The most common location is the right atrium, which needs to be differentiated from metastasis and primary cardiac angiosarcoma that usually involve the right side of the heart. The purpose of this study was to retrospectively evaluate the value of 18F-FDG PET/CT combined with contrast-enhanced CT in the differential diagnosis of cardiac lymphoma, primary cardiac sarcoma, and cardiac metastasis. Methods: Fifteen patients with cardiac lymphoma, 14 patients with primary cardiac sarcoma, and 19 patients with cardiac metastasis were retrospectively collected between January 2009 and November 2019. All patients underwent preoperative 18F-FDG PET/CT and contrast-enhanced CT, and the final diagnosis was confirmed by histopathology. The intensity- and volume-based PET parameters of cardiac lesions were analyzed. Intensity-based parameters included SUVmax, SUVmean, SUVpeak, and tumor-to-liver-ratio (TLR). The TLR was calculated by dividing the cardiac lesion SUVmax by the liver SUVmean. Volume-based parameters included metabolic tumor volume (MTV) and total lesion glycolysis (TLG). All parameters were assessed using Kruskal-Wallis test. Receiver operating characteristic (ROC) analysis was performed to determine the area under the ROC curve (AUC) for the above intensity- and volume-based parameters. The pleural effusion, pericardial effusion, and right coronary artery floating sign were visually analyzed on contrast-enhanced CT. Results: Cardiac lymphomas were all non-Hodgkin's lymphomas, including 6 primary cardiac lymphomas and 9 cases with lesions confined to the heart and mediastinal lymph nodes. Primary cardiac sarcomas included 9 angiosarcomas and 5 cases of rare-type sarcomas. Cardiac metastasis included 6 invasive thymomas, 6 thymic cancers, 3 primary germ cell tumors of the mediastinum, 2 para-mediastinal lung cancers, and 2 rare-type carcinomas. 80% (12/15) of patients with cardiac lymphoma have the right coronary artery floating sign, while none of the patients with sarcoma or metastasis have this sign. There was a significant difference of mean age in the primary cardiac sarcoma group (38.0 ± 14.47 years old) compared to the cardiac lymphoma (57.07 ± 16.10 years old) and cardiac metastasis groups (52.26 ± 12.15 years old) (P&lt;0.05) (Figure 1). Compared with primary cardiac sarcoma and cardiac metastasis, cardiac lymphoma had higher 18F-FDG uptake levels (SUVmax, SUVmean, SUVpeak, and TLR) (P&lt;0.05), but there was no significant difference between primary cardiac sarcoma and cardiac metastasis (P&gt;0.05) (Figure 2). Compared with primary cardiac sarcoma, cardiac lymphoma and cardiac metastasis had higher TLG and MTV (P&lt;0.05), but there was no significant difference between the latter two groups (P&gt;0.05) (Figure 3). The AUC value of SUVpeak is the highest for differentiation of cardiac lymphoma versus primary cardiac sarcoma (AUC = 0.952, P &lt; 0.001, 95% CI 0.803-0.997), versus cardiac metastasis (AUC = 0.893, P &lt; 0.001, 95% CI 0.739-0.972) by ROC analysis (Figure 4). And the corresponding optimal cutoff values of SUVpeak were 11.9 and 8.0, respectively, which could generate 80.0% sensitivity, 100% specificity, 100% positive predictive value, 82.4% negative predictive value, and 100.0% sensitivity, 68.4% specificity, 71.4% positive predictive value, 100.0% negative predictive value, respectively. There was no significant difference in the pleural and pericardial effusion among the three groups (P&gt;0.05). Conclusions The average age of patients with cardiac lymphoma and cardiac metastasis was significantly higher than that of patients with primary cardiac sarcoma. And the 18F-FDG uptake of cardiac lymphoma was significantly higher than that of primary cardiac sarcoma and cardiac metastasis, while MTV and TLG values of cardiac metastasis were higher than that of sarcoma. Combined with the right coronary artery floating sign, the above three kinds of malignancy can be identified. $$graphic_AFF47603-89E1-4974-B638-1430E46A0997$$ $$graphic_591882E8-E209-4D73-A1FA-45C4BCDAEA8D$$ $$graphic_CD69281F-3003-46D2-A6BE-EE12E10AA356$$ ER -