Characterization of uptake of 2-deoxy-2-[18F] fluoro-D-glucose by fungal-associated inflammation: the standardized uptake value is greater for lesions of blastomycosis than for lymphoma in dogs with naturally occurring disease.
OBJECTIVE
Based on limited reports, fungal lesions can have remarkably high intensity uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) on positron emission tomography (PET) images. The purpose of this investigation was to compare the standardized uptake value (SUV) of naturally occurring lesions of blastomycosis with the SUV of naturally occurring lymphoma in a series of dogs.


METHODS
Five dogs with naturally occurring blastomycosis and three dogs with lymphoma underwent whole-body FDG-PET prior to receiving any treatment for their disease.


RESULTS
The (mean +/- SD) SUV for 13 blastomycosis lesions was 7.7 +/- 2.0 versus a mean for 17 lymphomas of 4.8 +/- 1.8. These values were significantly different (P = 0.0537). There was overlap between the SUV of Blastomyces-associated lesions versus lymphomas, but a cut-off SUV of 7.0 was 100% specific for Blastomyces lesions. Numerous sites of disease were detected on the FDG-PET images that were not detected clinically.


CONCLUSIONS
FDG-PET is useful for determining the extent of disease in dogs with blastomycosis. The SUV for Blastomyces-associated lesions are as high or higher than for malignant lymphoma. Due to the similarities in canine and human blastomycosis and lymphomas, similar results would be predicted in human patients. In regions where blastomycosis is endemic, Blastomyces granulomas should be considered a differential diagnosis for lesions with high intensity uptake of FDG.
Bassett
Cary L M
CL
Department of Small Animal Clinical Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, USA. carybassett@duke .edu
Daniel
Gregory B
GB
Legendre
Alfred M
AM
Bochsler
Philip N
PN
Smith
Gary T
GT