Pulmonary nodules: differential diagnosis using 18F-fluorodeoxyglucose single-photon emission computed tomography.
OBJECTIVE
The objective of this study was to prospectively evaluate the feasibility and efficacy of single-photon emission computed tomography (SPECT) with 18F-fluorodeoxyglucose (FDG) for differentiating malignant from benign pulmonary nodules.


METHODS
Twenty-six patients with 28 radiologically indeterminate focal pulmonary lesions were examined. Fasting patients were injected with 5 MBq/kg of FDG (maximum dose, 370 MBq). Imaging was performed with dual-head SPECT cameras equipped with 511-keV collimators.


RESULTS
Seventeen of 21 pathologically malignant nodules showed FDG uptake on SPECT imaging (sensitivity, 81%). None of the seven benign modules showed uptake (specificity, 100%). SPECT imaging with FDG was positive in all 16 malignant nodules that were larger than or equal to 2 cm in diameter. However, only one (20%) of five nodules smaller than 2 cm in diameter showed positive on SPECT imaging.


CONCLUSIONS
Using current technology, we found FDG SPECT imaging useful for distinguishing benign from malignant pulmonary nodules that were larger than or equal to 2 cm in diameter. However, because of the relatively low sensitivity of SPECT, smaller malignant nodules were not adequately revealed.
Worsley
D F
DF
Division of Nuclear Medicine, Vancouver Hospital and Health Sciences Centre, B.C., Canada.
Celler
A
A
Adam
M J
MJ
Kwong
J S
JS
Müller
N L
NL
Coupland
D B
DB
Champion
P
P
Finley
R J
RJ
Evans
K G
KG
Lyster
D M
DM
D003847:Deoxyglucose / Q000031:analogs & derivatives*; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose