Camera-based FDG PET and 67Ga SPECT in evaluation of lymphoma: comparative study.
OBJECTIVE
To compare gallium 67 (67Ga) scintigraphy and camera-based fluorodeoxyglucose (FDG) positron emission tomography (PET) in the evaluation of patients with lymphoma.


METHODS
The performance of 67Ga scintigraphy and camera-based FDG PET in the detection of lymphoma was retrospectively evaluated and compared in 84 patients with lymphoma, with 219 suspected sites of disease. Eighty-nine percent of patients were examined during or after treatment. Camera-based FDG PET was initiated by equivocal characterization of the status of disease based on clinical, radiologic, and 67Ga scintigraphic assessment. Findings of 67Ga scintigraphy and camera-based FDG PET were compared on a per-patient and per-site basis for the whole group, for histologic subtypes, and for anatomic locations. Comparison of sensitivity, specificity, and accuracy between the two modalities for detection of lymphoma was performed with the McNemar test.


RESULTS
There was a statistically significant difference in sensitivity, specificity, and accuracy of 67Ga scintigraphy and camera-based FDG PET at both patient- and site-based analysis. 67Ga scintigraphy helped to accurately define disease state in 63% of patients and in 33% of sites, compared with 83% and 87%, respectively, for camera-based FDG PET. For discordant findings between the two modalities, camera-based FDG PET findings were confirmed as true-positive in 71% and as true-negative in 92% of patients. Camera-based FDG PET had a significantly higher detection rate for both nodal and extranodal lymphoma sites. It provided accurate assessment of lymphoma involvement of the skeleton in 93% of sites compared with 29% for 67Ga scintigraphy and excluded active lymphoma in 10 67Ga-positive benign parahilar sites.


CONCLUSIONS
In this selected group of patients with lymphoma, camera-based FDG PET allowed a significantly more accurate definition of active disease compared with that allowed with 67Ga scintigraphy.
Bar-Shalom
Rachel
R
Department of Nuclear Medicine, Rambam Medical Center and the Technion, Israel Institute of Technology, Bat Galim, Haifa 35254, Israel.
Yefremov
Nikolai
N
Haim
Nissim
N
Dann
Eldad J
EJ
Epelbaum
Ron
R
Keidar
Zohar
Z
Gaitini
Diana
D
Frenkel
Alex
A
Israel
Ora
O
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005710:Gallium Radioisotopes; D006801:Humans; D008223:Lymphoma / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014055:Tomography, Emission-Computed / Q000295:instrumentation*; D015899:Tomography, Emission-Computed, Single-Photon
D005710:Gallium Radioisotopes