Abstract
To determine the potential value of 13N-ammonia positron emission tomography (PET)/computed tomography (CT) myocardial perfusion imaging (MPI) for detection of myocardial perfusion changes at early stage induced by radiation damage. Methods: Thirty-six Beagle dogs were randomly divided into the control (n = 18) or the irradiation groups (n = 18). The irradiation group underwent local irradiation to the left ventricular anterior cardiac wall with a single dose of 20 Gy, whereas the control group received sham irradiation. All dogs underwent 13N-ammonia PET/CT MPI one week before irradiation and at three, six, and twelve month after sham or local irradiation. One week after completing 13N-ammonia PET/CT MPI examination, the irradiation group underwent coronary angiography examination. Six randomly selected Beagle dogs from each group were sacrificed and used to detect pathological cardiac injury at three, six, and twelve month after irradiation. Results: Compared with the control group and baseline, the irradiation group showed significantly increased perfusion in the irradiated area of the heart at three month after irradiation, perfusion reduction at six month after irradiation, and perfusion defect at twelve month after irradiation. There was no significant difference in the left ventricular ejection fraction (LVEF) values between the control and irradiation groups at baseline and at three month after irradiation. The irradiation group showed a reduction of LVEF compared with the control group at six (50.0 ± 8.1% vs. 59.3 ± 4.1%, P = 0.016) and twelve month (47.2 ± 6.7% vs. 57.4 ± 3.3%, P = 0.002) after irradiation. No coronary stenosis was observed in the irradiation group. Regional wall motion abnormalities appeared in the irradiated area at six month after irradiation and its extent was enlarged at twelve month after irradiation. Pathological changes were observed, radiation-induced myocardial tissue damage and microvascular fibrosis was progressively increased with time prolonged in the irradiated area. Conclusion: 13N-ammonia PET/CT MPI can dynamically detect myocardial perfusion changes together with global and regional left ventricular dysfunction induced by irradiation and may be a valuable method for monitoring radiation-induced heart disease (RIHD).
- Cardiology (basic/technical)
- PET/CT
- Radiation Safety
- 13N-ammonia PET/CT
- Radiotherapy
- myocardial perfusion imaging
- radiation-induced heart disease
- Copyright © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.