Utility of FDG-PET/CT in the diagnosis of IgG4-related diseases.

OBJECTIVES

The purpose of this work is to evaluate the usefulness of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging in management of IgG4-related disease (IgG4-RD) by retrospective analysis of PET/CT results in IgG4-RD patients.

METHODS

Twenty-six patients diagnosed with IgG4-RD according to Japanese diagnostic criteria who underwent 18F-FDG-PET/CT scans in the PLA General Hospital from January 2010 to May 2015 were enrolled in the study. Their clinical presentations and 18F-FDG-PET/CT findings were analysed.

RESULTS

A total of 26 patients (20 men; 6 women) with a mean age of 53.8 years (range 35-71 years) and mean treatment course of 7.1 months (range 0.33-72 months) who underwent 18F-FDG-PET/CT scans were analysed. CRP was relatively low in all patients (mean 0.79 mg/dl). 18F-FDG-PET/CT images confirmed that two or more organs were involved in all patients, and average SUV values for involved organs was 4.14 (range 0.30-8.78). Eleven patients were misdiagnosed with submandibular tumours, pancreatic cancer, pancreatitis, pulmonary interstitial fibrosis, retroperitoneal fibrosis or systemic vasculitis prior to 18F-FDG-PET/CT imaging.

CONCLUSIONS

18F-FDG-PET/CT imaging is a useful tool for the differential diagnosis of IgG4-RD, and for mapping involved organs, guiding biopsy, and monitoring treatment response.