Evaluation of semiquantitative assessments of fluorodeoxyglucose uptake on positron emission tomography scans for the diagnosis of pulmonary malignancies 1 to 3 cm in size.
BACKGROUND
To determine the optimal method of evaluating fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) for the diagnosis of pulmonary malignancies, the sensitivity and specificity of visual assessment and the several semiquantitative analyses were compared.


METHODS
Positron emission tomography data were analyzed for 130 pulmonary nodules from 1 to 3 cm in size (101 malignant and 29 benign nodules). The FDG uptake was measured by maximum standard uptake value (SUVmax), the contrast ratio (CR) of the SUV to the cerebellum (CR brain), and the CR of the SUV to the contralateral lung (CR lung). The CR lung was calculated from the SUV of the tumor (T) and that of the contralateral normal lung (N) and then was measured by two formulas, namely, T-N/T+N and T/N.


RESULTS
The sensitivities of both CR lung T-N/T+N and CR lung T/N were significantly higher than those of visual assessment, SUVmax, and CR brain (p = 0.01 to p < 0.001). No significant difference in sensitivity was observed between the CR lung T-N/T+N and CR lung T/N. Both CR lung T-N/T+N and CR lung T+N successfully imaged well-differentiated lung adenocarcinoma more frequently than the visual assessment, SUVmax, and CR brain (p = 0.002 to p < 0.001), whereas there were no significant differences of sensitivity among those five methods for the diagnosis of other histologic types of pulmonary malignancies.


CONCLUSIONS
The FDG uptake evaluated by the CR lung is superior to that evaluated using the visual assessment, SUVmax, and CR brain for the diagnosis of pulmonary malignancies, especially for well-differentiated lung adenocarcinoma. The simplified formula of CR lung with T/N can be used in place of that with T-N/T+N.
Ohba
Yasuomi
Y
Department of Thoracic Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan. loic.lang-lazdunski@gstt.nhs.uk
Nomori
Hiroaki
H
Shibata
Hidekatsu
H
Kobayashi
Hironori
H
Mori
Takeshi
T
Shiraishi
Shinya
S
Nakashima
Rumi
R
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18