The Application Of [¹⁸F]FDG-PET/CT In The Diagnosis And Treatment Of Dermatomyositis

Objective:To investigate the value of [18F]fluorodeoxyglucose-PET/CT ([18F]FDG-PET/CT) for the diagnosis and the prediction of remission time of dermatomyositis(DM), as well as its ability to evaluate the disease activity of DM. To determine the value of [18F]FDG-PET/CT for diagnosis of DM complicated with pulmonary interstitial diseases, analysis the prompting function of muscle SUV for DM with malignant diseases.Methods:DM patients admitted to the rheumatic department of PLA general hospital and underwent [18F]FDG-PET/CT examination were retrospectively reviewed between January 2012 to May 2015, sex- and age-matched Healthy controls (HC) were also enrolled. The standardized uptake value (SUV) of proximal limb girdle muscles in both groups were recorded and compared, so as will the differences between DM and subclinical DM. And then a correlation between the myodynamia of proximal limb girdle muscle, creatine kinase, kinase-MB, serum ferritin and SUV of each muscle group were analysied. At last, the differences of SUV in DM who experienced different remission time were also compared. To compare the SUV of lung in DM with interstitial lung disease or not, analyze the difference of muscle SUV between DM with malignant diseases and without malignant diseases.Results:(1) There were 58 patients of DM and 29 HC consecutively recruited in the study. The SUV of upper arm, shoulder and hip in classic DM were significantly higher than that in subclinical DM (p<0.05), similar results were found in patients who were initially treated, but the difference was not statistically significant (p>0.05).(2) The average SUV of evaluated muscle in DM group was significantly higher than that in HC group (p<0.001).(3) Receiver operating characteristic (ROC) analysis revealed the area under the curve (AUC) of abnormal SUV detected by [18F]FDG-PET/CT for diagnosing DM was 0.953. The myodynamia of upper arm and SUV was negatively related (p=-0.440, p=0.031). However, the levels of creatine kinase and SUV was positively related (p=0.500,p=0.013).(4) The average SUV of patients who experienced 3 months to remission was obviously less than that in patients who experienced 6 months to remission (p=0.015).(5) The lung SUV of DM with pulmonary interstitial diseases was significantly higher than DM without pulmonary interstitial disease(p<0.001); Receiver operating characteristic(ROC) analysis revealed the area under the curve(AUC) of lung SUV detected by [18F]FDG-PET/CT for diagnosing DM with pulmonary interstitial diseases was 0.969.(6) There was no difference in the SUV of muscle between DM with or without malignant diseases (p>0.05).Conclusion:(1) The SUV of proximal limb girdle muscle detected by [18F]FDG-PET/CT has a high diagnostic value for DM.(2) [18F]FDG-PET/CT can reflect disease activity, especially the SUV in upper arm.(3) [18F]FDG-PET/CT has important implications for the remission time of DM.(4) [18F]FDG-PET/CT for DM complicated with pulmonary interstitial diseases is of high value in the diagnosis, but muscle SUV cannot be prompted whether patients with malignant diseases or not.