[Incidence and etiological analysis of abnormal cardiac uptake in patients underwent oncologic PET/CT imaging]

Objective: To investigate the incidence, location and etiology of abnormal cardiac uptake in patients underwent oncologic ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography(PET/CT) imaging. Methods: The ¹⁸F-FDG PET/CT images of 2000 consecutive patients with suspected or diagnosed malignancy in Beijing Chaoyang Hospital from January 2014 to September 2016 were retrospectively analyzed. Fasting time was more than 12 hours before imaging, and fasting blood glucose level before ¹⁸F-FDG injection was less than 6.7 mmol/L. Focal uptake in the non-basal and non-papillary regions of the left ventricle, uptake in the right ventricle exceeding uptake in the left ventricle, and uptake in the atrium higher than that of the blood pool (when uptake of left ventricle was zero or low) were defined as abnormal, and all abnormal uptake was visually determined by experienced nuclear medicine physicians. General clinical data and the results of cardiac examination were collected to explore the incidence, location and etiology of cardiac diseases. Results: There were 138 patients with history of diabetes (6.90%), 228 patients with history of cardiovascular disease (11.40%) out of the 2 000 patients ((60.5±13.2) years, 1 117 male (55.85%)). The number and proportion of patients with malignancy, benign lesions, diseases of unknown etiology were 939 (46.95%), 484 (24.20%), 557 (28.85%), respectively. Abnormal cardiac uptake was detected in 145 patients (7.3%). The proportion of abnormal uptake in left ventricle, right ventricle and atrium was 52.4% (76 cases), 12.4% (18 cases), 35.2% (51 cases), respectively. Of the 76 individuals who had abnormal uptake in left ventricle, 25 cases (32.9%) were caused by coronary artery disease, and other causes included hypertrophic cardiomyopathy and myocardial damage caused by chemotherapy drugs, etc. Of the 18 cases who had abnormal uptake in right ventricle, 14 cases (14/18) were caused by pulmonary hypertension. In addition, 20 out of the 51 cases (39.3%) with abnormal uptake in atrium suffered from atrial fibrillation. Seventy-one patients with abnormal cardiac uptake (49.0%) had no clear manifestation and evidence of heart disease before imaging. Conclusions: The abnormal ¹⁸F-FDG uptake on oncologic PET/CT is not rare. The most common site of abnormal uptake is left ventricle, coronary artery disease, pulmonary hypertension and atrial fibrillation are common causes of abnormal ¹⁸F-FDG uptake.