Fluorodeoxyglucose positron emission tomography pattern of pulmonary lymphangitic carcinomatosis

Objective: The purpose of this study was to evaluate the F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) uptake in pulmonary lymphangific carcinomatosis identified on computed tomography (CT) in patients with lung cancer. Methods: This was a retrospective analysis of F-18-FDG PET images in 7 patients (4 male and 3 female, mean age: 56.6 +/- 6.6 years) with lung cancer with a CT-based diagnosis of lymphangitic carcinomatosis. The F-18-FDG PET scans in a group of 7 patients (4 male and 3 female, mean age: 42.1 +/- 5.66 years) with normal chest CT scans served as a control group. Mean standardized uptake values (SUVs) were calculated based on average tumor uptake, initial injected activity, and body weight. Results: The intensity of F-18-FDG uptake in diseased lung is significantly greater than in corresponding normal contralateral lung or in the lungs of normal controls (P = 0.003). The ratio of the SUV of lung with lymphangitic carcinomatosis to corresponding contralateral normal lung was significantly increased (P = 0.006), and the ratio of the SUV of mediastinal blood pool to lung with lymphangitic carcinomatosis was significantly decreased (P = 0.0002). Conclusion: There is diffuse increased FDG uptake in the lung corresponding to the CT pattern of lymphangific carcinomatosis.