Value of delayed 18F-FDG PET in the diagnosis of solitary pulmonary nodule.

Performing dual point 18F-FDG PET scans of solitary pulmonary nodules at an initial SUV (max) <2.5 is a useful technique. However, prolonging second image acquisition from 120 to 180 min does not appear to improve accuracy. Dual time 18F-FDG PET is not useful in differentiating benign and malignant pulmonary nodules with an initial mean SUV ≤2.5 in parts of the world where granulomatous disease is prevalent. Prolonged imaging on PET scanners is expensive particularly where availability if these scanners is limited. Further prospective research is required to define the potential benefits of dual time point 18F-FDG PET imaging, before recommending routine use of the technique.