title: The Clinical Usefulness of (18)F-FDG PET/CT in Patients with Systemic Autoimmune Disease.
abstract: OBJECTIVE
  Individuals with systemic autoimmune disease have an increased susceptibility to both inflammation and malignancy. The aim of this study was to evaluate the clinical usefulness of (18)F-FDG PET/CT in patients with systemic autoimmune disease.
  
  
  METHODS
  Forty patients diagnosed with systemic autoimmune disease were enrolled. Diagnostic accuracy of FDG PET/CT for detecting malignancy was assessed. FDG PET/CT findings, including maximum standardized uptake (SUVmax) of lymphadenopathy (LAP), liver, bone marrow, spleen, joint and muscles, were considered for the characterization of LAPs.
  
  
  RESULTS
  FDG PET/CT could detect metabolically activated lesions in 36 out of 40 patients (90%) including inflammatory lesions in 28 out of 32 patients (88%). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG PET/CT for the detection of malignancy were 100, 67, 70, 25, and 100%, respectively. Multiple LAPs were found in 25 of 40 patients (63%), and comprised three malignancies, four cases of tuberculosis, and 18 reactive changes. A SUVmax ratio of bone marrow to liver below 0.78 could distinguish malignancy from tuberculosis + reactive change (AUC = 1.000, sensitivity: 100%, specificity: 100%). The SUVmax ratio of spleen to liver in the reactive group was also significantly higher than that in the malignancy group (P = 0.014). SUVmax of LAP in the TB group was significantly higher than that in the reactive group (P = 0.040).
  
  
  CONCLUSIONS
  PET/CT is useful in detecting and differentiating inflammation and malignancy in patients with systemic autoimmune disease. Frequent false-positive interpretations can be minimized by consideration of FDG uptake in bone marrow and spleen.
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School and Hospital, 8 Hakdong, Dongku, Gwangju 501-757 South Korea.
authors.forename: Jong-Ryool
authors.initials: JR
authors.lastname: Oh
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School and Hospital, 8 Hakdong, Dongku, Gwangju 501-757 South Korea.
authors.forename: Ho-Chun
authors.initials: HC
authors.lastname: Song
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School and Hospital, 8 Hakdong, Dongku, Gwangju 501-757 South Korea.
authors.forename: Sae-Ryung
authors.initials: SR
authors.lastname: Kang
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School and Hospital, 8 Hakdong, Dongku, Gwangju 501-757 South Korea.
authors.forename: Su-Woong
authors.initials: SW
authors.lastname: Yoo
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School and Hospital, 8 Hakdong, Dongku, Gwangju 501-757 South Korea.
authors.forename: Jahae
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School and Hospital, 8 Hakdong, Dongku, Gwangju 501-757 South Korea.
authors.forename: Ari
authors.initials: A
authors.lastname: Chong
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School and Hospital, 8 Hakdong, Dongku, Gwangju 501-757 South Korea.
authors.forename: Jung-Joon
authors.initials: JJ
authors.lastname: Min
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School and Hospital, 8 Hakdong, Dongku, Gwangju 501-757 South Korea.
authors.forename: Hee-Seung
authors.initials: HS
authors.lastname: Bom
authors.affiliation: Department of Rheumatology, Chonnam National University Hospital, Gwangju, South Korea.
authors.forename: Shin-Seok
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Department of Rheumatology, Chonnam National University Hospital, Gwangju, South Korea.
authors.forename: Yong-Wook
authors.initials: YW
authors.lastname: Park
keywords: Autoimmune disease; Neoplasms; PET/CT; Reactive lymphoid hyperplasia; Tuberculosis