Clinical value of 18F-FDG PET/CT in distinguishing benign from malignant cardiac tumors / 中华核医学与分子影像杂志

ABSTRACT

Objective:To evaluate the clinical value of 18F-fluorodexoyglucose (FDG) PET/CT in distinguishing benign from malignant tumors in patients with cardiac tumors. Methods:Between January 2015 and September 2018, 18F-FDG PET/CT was performed in 3 678 patents in Beijing Anzhen Hospital, and 51 of them (51/3 678, 1.39%) were diagnosed as cardiac tumors. Finally, 28 patients (10 males, 18 females; mean age (52±14) years, age range 18-84 years) with pathological results were included. According to pathological results, patients were divided into 4 groups group 1 with primary benign cardiac tumor ( n=9), group 2 with primary malignant cardiac tumor ( n=9), group 3 with lymphoma ( n=6) and group 4 with secondary malignant cardiac tumor ( n=4). All patients underwent early (60 min) 18F-FDG PET/CT imaging and 22 patients (6, 7, 6, 3 patients in group 1, group 2, group 3, group 4 respectively) underwent delayed (120 min) imaging. The maximum standardized uptake value (SUV max) and target/backgroud ratio (TBR) of 4 groups in early imaging and delayed imaging were calculated and compared with one-way analysis of viariace and Scheffe Post-hoc test. TBR were calcualted as SUV max/mean standardized uptake value (SUV mean) in the liver. Receiver operating characteristic (ROC) curve analysis was also performed. Results:SUV max during early imaging, defined SUV max(early), was 2.6±1.5, 9.9±4.0, 20.5±6.1, 9.2±5.8 in group 1-4 respectively ( F=21.39, P<0.01), the value of group 1 was lower than that of group 2 and 3, and the value of group 3 was the highest (all P<0.005). TBR early was 1.1±0.6, 4.1±1.6, 9.4±2.6, 3.7±2.0 in the 4 groups ( F=29.15, P<0.01), the value of group 1 was lower than that of group 2 and 3, and the value of group 3 was the highest (all P<0.005). SUV max in delayed imaging (SUV max(delay)) was 2.4±1.2, 11.0±5.9, 25.8±7.7, 13.7±7.7 respectively in the 4 groups ( F=16.01, P<0.01). TBR delay was also significantly different among the 4 groups (1.3±0.7, 5.5±2.9, 14.4±4.9, 7.9±5.0; F=14.78, P<0.01), the value of group 3 was higher than that of group 1 and 2 (all P<0.05). ROC curve analysis showed optimal cut-off values for indicating malignancy were SUV max(early)=4.2, TBR early=1.6, SUV max(delay)=4.6, TBR delay=1.9. The corresponding sensitivities, specificities, accuracies were 19/19, 8/9, 96.4%(27/28); 19/19, 7/9, 92.9%(26/28); 16/16, 6/6, 100%(22/22); 16/16, 5/6, 95.5%(21/22), respectively. Conclusions:18F-FDG PET/CT imaging can accurately diagnose malignant cardiac tumors. Delayed imaging can further improve the accuracy for diagnosis of malignant cardiac tumors.