PURPOSE
To compare 2-deoxy-2-[fluorine-18]fluoro-D-glucose (FDG) positron emission tomography (PET) with computed tomography (CT) in primary nodal staging of malignant lymphoma.
MATERIALS AND METHODS
Sixty consecutive patients with untreated, histopathologically proved malignant lymphoma (aged 7-72 years; 33 with non-Hodgkin lymphoma, 27 with Hodgkin disease) underwent FDG PET and contrast material-enhanced CT for nodal staging. Lymph node regions identified at both CT and PET were regarded as actual locations of disease. Discordant results were verified with biopsy or clinical follow-up whenever possible.
RESULTS
One hundred sixty of 740 evaluated lymph node regions were identified as diseased at both CT and PET. Of the 25 additional regions seen with PET, seven were true-positive; two, false-positive; and 16, unresolved. CT showed six additional disease manifestations; three were false-positive, and three were unresolved. Staging was changed in the four patients with the seven confirmed additional PET findings: from stage I to II in one patient and from stage II to III in three patients. Staging was changed from stage II to I in one of the three patients with false-positive CT findings.
CONCLUSION
FDG PET may be more accurate for detecting nodal lymphoma than incremental CT.