title: 18F-FDG PET is superior to 67Ga SPECT in the staging of non-Hodgkin's lymphoma.
abstract: OBJECTIVE
  Our study aims to compare diagnostic accuracy between 18F-FDG PET and 67Ga SPECT in the staging of non-Hodgkin's lymphoma.
  
  
  METHODS
  Twenty-eight patients with non-Hodgkin's lymphoma, underwent 18F-FDG PET, 67Ga SPECT and CT for the pretreatment staging of malignant lymphoma between August 1999 and March 2002. 18F-FDG PET imaging was obtained 60 minutes after the intravenous administration of 185 MBq of 18F-FDG. 67Ga SPECT imaging was obtained 2 days after the intravenous administration of 148 MBq of 67Ga. 18F-FDG PET and 67Ga SPECT were performed within one month. Both imagings were performed on the area from the neck to the pelvis. The 18F-FDG PET and 67Ga SPECT findings were compared with the CT findings and the clinical course.
  
  
  RESULTS
  Sixty-six nodal lesions were clinically confirmed. Of these, 32 were identified by both 18F-FDG PET and 67Ga SPECT. The remaining 34 lesions were identified only by 18F-FDG PET. The mean (+/- SD) sizes' of the nodes were 34.7 +/- 32.4 mm for 18F-FDG-positive and 67Ga-positive lesions and 15.7 +/- 8.3 mm for 18F-FDG-positive and 67Ga-negative lesions (p < 0.001). Of the 23 extranodal lesions, 12 were identified by both 18F-FDG PET and 67Ga SPECT, whereas 6 lesions were identified by only 18F-FDG PET. Five lesions were not identified by either technique. No 18F-FDG-negative but 67Ga-positive nodal or extranodal lesions were observed. The difference in findings between the two studies is related to the difference in the size but not in the histology or site of the lesions.
  
  
  CONCLUSIONS
  18F-FDG PET detected significantly more lesions particularly small lesions than 67Ga SPECT. Thus, 18F-FDG PET is considered to be superior to 67Ga SPECT in the staging of non-Hodgkin' s lymphoma.
authors.affiliation: Third Department of Internal Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan. fumiyasu@xb4.so-net.ne.jp
authors.forename: Fumiyasu
authors.initials: F
authors.lastname: Yamamoto
authors.forename: Eriko
authors.initials: E
authors.lastname: Tsukamoto
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Nakada
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takei
authors.forename: Songji
authors.initials: S
authors.lastname: Zhao
authors.forename: Masahiro
authors.initials: M
authors.lastname: Asaka
authors.forename: Nagara
authors.initials: N
authors.lastname: Tamaki
mesh_terms: D002951:Citrates; D019788:Fluorodeoxyglucose F18; D005708:Gallium; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000473:pathology*; D009367:Neoplasm Staging / Q000379:methods; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D002951:Citrates; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005708:Gallium; C103850:gallium citrate