Utility of 18 F-FDG PET/CT in early detection of radiation-induced heart disease in Beagle dogs / 中华核医学与分子影像杂志

ABSTRACT

Objective To establish radiation-induced heart disease ( RIHD) Beagle models, in-vestigate the efficacy of 18 F-FDG PET/CT in the detection of RIHD and observe the pathological changes. Methods The ventricular anterior wall of 12 Beagle dogs were X-ray irradiated locally with a single dose of 20 Gy. 18 F-FDG PET/CT and echocardiography were performed at baseline and 3 months after radiation. ROI was drawn on the irradiation field and the non-irradiation field ( the posterior wall of left ventricle) to obtain the SUVmax . Then the SUVmax ratio of the irradiation field to the non-irradiation field ( INR) was cal-culated. The left ventricular function parameters before and after radiation were obtained by echocardio-graphy. Within 1 week after the imaging examinations were finished, the dogs were sacrificed, and hearts were taken out to perform pathological observation. Paired t test was used to analyze the data. Results High 18 F-FDG uptake in the irradiation field was shown 3 months after radiation. The average INRs before and after radiation were 0.99±0.15 and 2.54±0.43 respectively (t=7.021, P=0.001). No significant difference was ob-served on cardiac function parameters between baseline and 3 months after radiation( t valuesfrom-1.253 to-0.786, all P>0.05) . The pathological results showed a few degenerated myocytes, increased thickness of myocardial vascular walls in irradiated myocardium. Conclusions 18 F-FDG PET/CT can detect early RIHD before abnormal cardiac function. Increased 18 F-FDG uptake in irradiated field may be related to myocardial ischemia which results from microvascular damage by radiation.