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Detection of Myocardial Metabolic Abnormalities by 18F-FDG PET/CT and Corresponding Pathological Changes in Beagles with Local Heart Irradiation.

Yan R, Song J, Wu Z, Guo M, Liu J, Li J, Hao X, Li S - Korean J Radiol (2015)

Bottom Line: 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.An F-HFD preparation protocol used before obtaining PET/CT can improve the sensitivity of the detection of cardiotoxicity associated with radiotherapy.

View Article: PubMed Central - PubMed

Affiliation: Nursing College of Shanxi Medical University, Taiyuan 030001, China. ; Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, China.

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.

Materials and 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.

Conclusion: 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.

No MeSH data available.


Related in: MedlinePlus

Images of male beagle (M2) at baseline and 3 months after RT using F-HFD protocol.A. Dose-distribution axial image. B. Cardiac FDG-PET/CT axial images before RT. C. Cardiac FDG-PET/CT axial images 3 months after RT. D. Myovation images of FDG at 3 months after RT. B shows suppression of myocardial FDG uptake before RT. C and D show high FDG uptake (arrows) corresponding to irradiated field 3 months after RT. FDG = fluorodeoxyglucose, F-HFD = fasting followed by a high-fat diet, PET/CT = positron emission tomography/computed tomography, RT = radiotherapy
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Figure 3: Images of male beagle (M2) at baseline and 3 months after RT using F-HFD protocol.A. Dose-distribution axial image. B. Cardiac FDG-PET/CT axial images before RT. C. Cardiac FDG-PET/CT axial images 3 months after RT. D. Myovation images of FDG at 3 months after RT. B shows suppression of myocardial FDG uptake before RT. C and D show high FDG uptake (arrows) corresponding to irradiated field 3 months after RT. FDG = fluorodeoxyglucose, F-HFD = fasting followed by a high-fat diet, PET/CT = positron emission tomography/computed tomography, RT = radiotherapy

Mentions: No abnormal 18F-FDG uptake in the myocardium was found before RT. However, 3 months after RT, high 18F-FDG uptake in the anterior myocardium corresponding to the irradiated field was observed compared to outside of the irradiated field (Fig. 3). Cases with higher 18F-FDG uptake in the irradiated field than in other areas were diagnosed as positive; otherwise, the cases were deemed to be as negative. The F-HFD protocol detected a more positive rate than did the 12H-F protocols (10/12 vs. 4/12, respectively; p = 0.031; McNemar test) (Fig. 4, Table 2).


Detection of Myocardial Metabolic Abnormalities by 18F-FDG PET/CT and Corresponding Pathological Changes in Beagles with Local Heart Irradiation.

Yan R, Song J, Wu Z, Guo M, Liu J, Li J, Hao X, Li S - Korean J Radiol (2015)

Images of male beagle (M2) at baseline and 3 months after RT using F-HFD protocol.A. Dose-distribution axial image. B. Cardiac FDG-PET/CT axial images before RT. C. Cardiac FDG-PET/CT axial images 3 months after RT. D. Myovation images of FDG at 3 months after RT. B shows suppression of myocardial FDG uptake before RT. C and D show high FDG uptake (arrows) corresponding to irradiated field 3 months after RT. FDG = fluorodeoxyglucose, F-HFD = fasting followed by a high-fat diet, PET/CT = positron emission tomography/computed tomography, RT = radiotherapy
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4499559&req=5

Figure 3: Images of male beagle (M2) at baseline and 3 months after RT using F-HFD protocol.A. Dose-distribution axial image. B. Cardiac FDG-PET/CT axial images before RT. C. Cardiac FDG-PET/CT axial images 3 months after RT. D. Myovation images of FDG at 3 months after RT. B shows suppression of myocardial FDG uptake before RT. C and D show high FDG uptake (arrows) corresponding to irradiated field 3 months after RT. FDG = fluorodeoxyglucose, F-HFD = fasting followed by a high-fat diet, PET/CT = positron emission tomography/computed tomography, RT = radiotherapy
Mentions: No abnormal 18F-FDG uptake in the myocardium was found before RT. However, 3 months after RT, high 18F-FDG uptake in the anterior myocardium corresponding to the irradiated field was observed compared to outside of the irradiated field (Fig. 3). Cases with higher 18F-FDG uptake in the irradiated field than in other areas were diagnosed as positive; otherwise, the cases were deemed to be as negative. The F-HFD protocol detected a more positive rate than did the 12H-F protocols (10/12 vs. 4/12, respectively; p = 0.031; McNemar test) (Fig. 4, Table 2).

Bottom Line: 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.An F-HFD preparation protocol used before obtaining PET/CT can improve the sensitivity of the detection of cardiotoxicity associated with radiotherapy.

View Article: PubMed Central - PubMed

Affiliation: Nursing College of Shanxi Medical University, Taiyuan 030001, China. ; Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, China.

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.

Materials and 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.

Conclusion: 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.

No MeSH data available.


Related in: MedlinePlus