Routine use of dual time ¹⁸F-FDG PET for staging of preoperative lung cancer: does it affect clinical management?

The objective of this study was to compare the diagnostic accuracy of dual-time-point 18F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) to single-time-point (18)F-FDG PET for staging of preoperative lung cancer.

Between November 2008 and December 2009, 107 patients who were diagnosed as having lung cancer or strongly suspected of having lung cancer were enrolled. They underwent dual-time-point (18)F-FDG PET following conventional imaging. Dual-time-point (18)F-FDG PET imaging (whole body) was performed at 1-h (early) post-FDG injection and repeated (2 h delayed) after injection. The diagnostic accuracy of pre-PET staging and post-PET staging was retrospectively evaluated, and the diagnostic accuracy of dual-time-point (18)F-FDG PET was compared to that of single-time-point (18)F-FDG PET.

In 100 patients, the early (18)F-FDG PET scan resulted in upstaging of the tumor in ten (10 %) and down-staging of the tumor in five (5 %) compared to the conventional scan. The delayed phase of (18)F-FDG PET provided no additional information on staging for lung cancer patients. The remaining seven patients were diagnosed as not having lung cancer.

This study confirmed that dual-time-point (18)F-FDG PET is useful for differential diagnosis between benign and malignant lesions, but has no major impact on staging and therapeutic management of patients with pathologically proven lung cancer.