FDG positron emission tomography imaging of drug-induced pneumonitis.

Several studies have reported the findings of fluorine-18-labeled fluoro-2-deoxy-D: -glucose positron emission tomography (FDG-PET) in benign lung disease with diffuse pulmonary injury; however, the characteristics and effectiveness of FDG-PET imaging for interstitial pneumonitis have not been substantiated. We report two cases of drug-induced pneumonitis in two patients treated for breast cancer who were diagnosed by FDG-PET examination. Both the cases showed diffuse interstitial infiltration in the bilateral lungs on computed tomography, but the degree of FDG accumulation was different. It is probable that the degree of FDG accumulation reflected the activity of the drug-induced pneumonitis. The present cases show very interesting FDG-PET imaging findings of diffuse lung disease.