Multiple values of 18F-FDG PET/CT in idiopathic inflammatory myopathy

Abstract

This study aimed to investigate the multiple values of F-FDG PET/CT in detecting malignant tumors, evaluating myopathy, and determining interstitial lung disease in patients with idiopathic inflammatory myopathy (IIM). We retrospectively analyzed the data of 38 patients who were examined byF-FDG PET/CT and eventually diagnosed as IIM. We also collected the data of another 22 cases with negative PET/CT as the control. Pulmonary HRCT images were acquired simultaneously with regular F-FDG PET/CT imaging for each patient. Image analysis included the presence of malignant lesions, muscular FDG uptake, and interstitial lung disease and its imaging features. IIM was classified into polymyositis (PM), classic dermatomyositis (CDM), and clinical amyopathic dermatomyositis (CADM). All suspected malignant lesions were confirmed by histopathological examination. Interstitial lung disease was diagnosed by HRCT. Rapidly progressive interstitial lung disease (RP-ILD) was determined according to clinical follow-ups. The significance ofF-FDG PET/CT in the detection of malignancy, observation of activity of myopathy, and determination of interstitial lung disease in IIM patients was explored based on the final clinical diagnosis. In the 38 patients with IIM, 3 cases were classified as PM, 18 as CDM, and 17 as CADM. PET/CT correctly detected 7 cases (18.4%) of malignant tumors, and all of which were found in CDM and PM patients. The muscular FDG uptake in IIM patients was higher than the control population, and it was higher in patients with myopathy (including PM and CDM) than in patients with CADM. The muscular FDG uptake in IIM patients was correlated with elevated serum creatine kinase level (r = 0.332, P = 0.042) and impaired muscle strength (r = -0.605, P < 0.001). Interstitial lung disease was detected by HRCT in 30 patients (78.9%), and 7 of them were eventually confirmed as RP-ILD, according to the clinical outcome. The FDG uptake in lung lesions of RP-ILD patients was higher than those with chronic interstitial lung diseases, even though no significant difference was found between the CT features of RP-ILD and chronic interstitial lung disease. When SUV ≥ 2.4 was employed as the threshold for RP-ILD prediction, the diagnostic efficiency was yield with a sensitivity of 100.0% (7/7), specificity of 87.0% (20/23), and accuracy of 90.0% (27/30), respectively. For IIM patients, F-FDG PET/CT has multiple values in identifying malignancies, observing the status of inflammatory myopathy, detecting interstitial lung disease, and predicting the occurrence of RP-ILD. Therefore, it is recommended to use PET/CT in the clinical course of diagnosis and management of IIM.

Visualisation of interstitial lung disease by molecular imaging of integrin αvβ3 and somatostatin receptor 2

“…Thus, the performance of our radiotracers should ideally have been evaluated in a second, multisystemic animal model, which better reflects the human situation in CTD-ILD. However, the available literature on PET/CT imaging provides substantial evidence that even in patients with CTD with multiorgan involvement, ILD can reliably be diagnosed 58–65…”

Value of 18F-FDG PET/CT in the detection of occult malignancy in patients with dermatomyositis

“…In 1916, Stertz reported the comorbidity of DM and malignant tumors for the first time [6]. Since then, increasing number of similar reports appeared which attracted clinical physician attention [7,8,9,10,11,12]. The risk of malignant tumors in the DM patients is approximately 1.8-3.6 folds of the general population [13].…”

Nuclear matrix protein 2 antibody-positive adult dermatomyositis: a case report and review of the literature

“…For adult patients with NXP-2-positive dermatomyositis, age-appropriate screening and symptom-targeted malignancy screening may be insufficient in detecting underlying malignancy. Thus, patients may require full-body imaging with MRI, CT, or PET-CT [10][11][12].…”