Benign and malignant pulmonary lesions usually are differentiated by 18F-FDG PET with a semiquantitative 18F-FDG standardized uptake value (SUV) of 2.5. However, the frequency of malignancies with an SUV of less than 2.5 is significant, and pulmonary nodules with low 18F-FDG uptake often present diagnostic challenges. These results suggested that for solid pulmonary lesions with low 18F-FDG uptake, semiquantitative approaches do not improve the accuracy of 18F-FDG PET over that obtained with visual analysis. Pulmonary lesions with visually absent uptake indicate that the probability of malignancies is very low. In contrast, the probability of malignancy in any visually evident lesion is about 60%.
Reference-Accuracy of PET for Diagnosis of Solid Pulmonary Lesions with 18F-FDG Uptake Below the Standardized Uptake Value of 2.5
Journal of Nuclear Medicine Vol. 47 No. 3 426-431