Background: To investigate SUVmax of same lung cancer patients who underwent PET-CT with both TOF and non-TOF iterative reconstructions using the same machine. Methods: We performed list mode PET-CT scan of the chest at 1 hr post injection of 370 MBq (10 mCi) of F-18 FDG under fasting condition. The SUVmax was measured in lung cancer during radiation therapy on ungated PET-CT images using TOF and non-TOF iterative reconstructions in a Philips Big Bore PET-CT system. We measured 94 pairs of SUVmax in TOF and non-TOF PET images from the same patient.
Results: The paired t-test showed significant variability of SUVmax between TOF and non-TOF images at 1 hr post injection ( P<0.0001).
Conclusion: While image quality may be improved with PET scanners having TOF options, the SUVmax is in general higher in non-TOF reconstruction. Recognition of such differences is important when patients are seamed multiple times during the course of their disease.