title: Comparison of 18F-fluoro-2-deoxyglucose positron emission tomography and gallium-67 citrate scintigraphy for detecting malignant lymphoma.
abstract: This study evaluates and compares the accuracy of positron emission tomography with 18F-fluoro-2-deoxyglucose (FDG-PET) and gallium-67 citrate (Ga-67) scintigraphy in identifying disease sites in patients with malignant lymphoma at initial diagnosis or relapse. Histology subgroups included low (n=5), intermediate (n=6), high-grade (n=5) non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) (n=14). Ann-Arbor staging included 7 patients in stage I, 8 in stage II, 9 in stage II, 6 in stage IV and 11 extra-nodal. In this study, before any therapy, 25 contemporaneous FDG-PET and Ga-67 scintigraphies were performed on patients with either NHL (16) or HD (14). One hundred and eleven sites of disease were correlated on a site-by-site basis in corresponding areas of FDG-PET and Ga-67 scintigraphy. Discordant FDG-PET and Ga-67 scintigraphic findings were correlated with CT/MRI and clinical evaluation. FDG-PET detected malignant lymphoma in 24/25 patients (sensitivity: 96.0%). There was a false-negative FDG-PET result in only 1 patient with low-grade gastric malignant lymphoma. Ga-67 scintigraphy detected malignant lymphoma in 18/25 patients (sensitivity: 72.0%). There were false-negative Ga-67 scintigraphic results in 4 cases with low-grade non-Hodgkin's lymphoma, 2 cases with bone or bone marrow involvement, and 3 smaller disease sites. FDG-PET upstaged 6 patients in whom Ga-67 scintigraphy detected disease sites partially. In imaging lymphoma prior to therapy, FDG-PET had a higher sensitivity and detected significantly more disease sites when compared with Ga-67 scintigraphy in the initial evaluation of this group of patients. Upstaging of patients with FDG-PET may result in a change in treatment strategy. However, evaluation of the final sensitivity, specificity and accuracy of these imaging modalities will need a further study with a larger patient number.
authors.affiliation: Department of Nuclear Medicine and PET Center, Shin Kong Wu Ho-Su Memorial Hospital, Taiwan.
authors.forename: Yeh-You
authors.initials: YY
authors.lastname: Shen
authors.forename: Albert
authors.initials: A
authors.lastname: Kao
authors.forename: Ruoh-Fang
authors.initials: RF
authors.lastname: Yen
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D005710:Gallium Radioisotopes; D006689:Hodgkin Disease / Q000000981:diagnostic imaging*; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed / Q000379:methods*
chemical_list: D005710:Gallium Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18