Assessing the Clinical Feasibility of Whole-Body Dynamic FDG PET Imaging

Objectives: In current standard of care (SOC) PET imaging for tumor assessment, a single timepoint of radiotracer distribution is acquired starting at ~60 minutes (min) post 18F-fluorodeoxyglucose (FDG) administration. Recently, whole-body dynamic (WBD) PET imaging has been proposed as an alternative to SOC imaging, in which short time interval whole-body PET scans (e.g. 30 sec/bed position for WBD versus 3-5 min/bed position in SOC) are obtained and repeated multiple times during an exam. The multi-pass whole body PET images can be used to model dynamic aspects of the radiotracer in addition to creation of averaged standardized-uptake value (WBD SUV) PET images similar to conventional SOC PET images. While WBD SUV images often have similar total counts to SOC imaging, there is a greater risk of motion between whole-body passes. In this study, we assessed the clinical feasibility of WBD PET imaging by comparing the image quality of PET WBD SUV images to SOC PET images. Methods: Nineteen subjects with a prior cancer diagnosis were enrolled. Each subject underwent WBD PET imaging starting at ~30 min after FDG administration on either a GE PET/CT scanner (N=8) or a GE Signa PET/MR scanner (N=11), followed by SOC PET imaging starting at ~60 min post administration on a GE PET/CT scanner. Each set of WBD SUV PET images consisted of 4-7 whole body passes which were decay corrected, averaged, and normalized to create WBD SUV images. Image quality was compared between SOC and WBD SUV PET images using a 5-point Likert scale by 2 blinded nuclear medicine physicians. Motion artifacts were also assessed as being absent, mild, or severe. Results: The SOC and WBD SUV images were scored to have either good or excellent quality, which were of diagnostic quality in all 19 cases (Table 1). Image quality was degraded in one WBD case due to significant head motion, but the motion did not impact image quality in the body (Table 2). In all other cases, WBD SUV images were scored as equivalent to SOC images in image quality (Figure 1, Example WBD SUV and SOC PET), and motion artifacts were either none or mild. Conclusions: WBD SUV PET images are comparable in image quality to SOC PET image in the body. WBD PET imaging is a promising alternative to SOC PET, yielding whole-body pharmacokinetic information in addition to high quality diagnostic PET images. Research Support: This research was supported by the UW Shapiro Medical Student Summer Research Fellowship Award and in part by