title: Detection of Myocardial Metabolic Abnormalities by 18F-FDG PET/CT and Corresponding Pathological Changes in Beagles with Local Heart Irradiation.
abstract: OBJECTIVE
  To determine the efficacy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the detection of radiation-induced myocardial damage in beagles by comparing two pre-scan preparation protocols as well as to determine the correlation between abnormal myocardial FDG uptake and pathological findings.
  
  
  METHODS
  The anterior myocardium of 12 beagles received radiotherapy locally with a single X-ray dose of 20 Gy. 18F-FDG cardiac PET/CT was performed at baseline and 3 months after radiation. Twelve beagles underwent two protocols before PET/CT: 12 hours of fasting (12H-F), 12H-F followed by a high-fat diet (F-HFD). Regions of interest were drawn on the irradiation and the non-irradiation fields to obtain their maximal standardized uptake values (SUVmax). Then the ratio of the SUV of the irradiation to the non-irradiation fields (INR) was computed. Histopathological changes were identified by light and electron microscopy.
  
  
  RESULTS
  Using the 12H-F protocol, the average INRs were 1.18 ± 0.10 and 1.41 ± 0.18 before and after irradiation, respectively (p = 0.021). Using the F-HFD protocol, the average INRs were 0.99 ± 0.15 and 2.54 ± 0.43, respectively (p < 0.001). High FDG uptake in irradiation field was detected in 33.3% (4/12) of 12H-F protocol and 83.3% (10/12) of F-HFD protocol in visual analysis, respectively (p = 0.031). The pathology of the irradiated myocardium showed obvious perivascular fibrosis and changes in mitochondrial vacuoles.
  
  
  CONCLUSIONS
  High FDG uptake in an irradiated field may be related with radiation-induced myocardial damage resulting from microvascular damage and mitochondrial injury. An F-HFD preparation protocol used before obtaining PET/CT can improve the sensitivity of the detection of cardiotoxicity associated with radiotherapy.
authors.affiliation: Nursing College of Shanxi Medical University, Taiyuan 030001, China. ; Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Yan
authors.affiliation: Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Cardiology, First Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Min
authors.initials: M
authors.lastname: Guo
authors.affiliation: Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Radiological and Environmental Medicine, China Institute for Radiation Protection, Taiyuan 030006, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Xinzhong
authors.initials: X
authors.lastname: Hao
authors.affiliation: Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Sijin
authors.initials: S
authors.lastname: Li
mesh_terms: D000818:Animals; D004285:Dogs; D005215:Fasting; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006321:Heart / Q000000981:diagnostic imaging*; D006335:Heart Injuries / Q000000981:diagnostic imaging*; D008297:Male; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D011832:Radiation Injuries / Q000175:diagnosis / Q000000981:diagnostic imaging*; D013899:Thoracic Neoplasms / Q000532:radiotherapy; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG PET/CT; Pathology; Radiation-induced heart disease; Radiotherapy