Ultralow-dose [F]FDG PET/CT Imaging: Demonstration of Feasibility in Dynamic and Static Images

Objectives: Validation of [F]FDG PET/CT at ultralow-dose (0.37 MBq/kg) and compared to imaging at half-dose (1.85 MBq/kg).

Methods: This prospective head-to-head intraindividual study compared dynamic and static parameters of ultralow-dose with half-dose [F]FDG total-body PET/CT. In static imaging, the ultralow-dose groups of PET images were denoted ULD5, 60-65 min; ULD8, 60-68 min; ULD10, 60-70 min; and ULD15, 60-75 min. The half-dose group images were reconstructed to 60-61, 60-62, 60-63, and 60-75 min, defined as LD1, LD2, LD3, and LD15, respectively. A 5-point Likert scale was used to subjectively evaluate the quality of static PET images, with a score greater than 3 considered to meet the requirements for clinical diagnosis.

Results: Thirty participants were included in this study, and in terms of kinetic indicators, no special differences were found between the two groups of normal organs and lesions. In static images, those in groups ULD8 and LD2 achieved scores of [Formula: see text] 3.0, meeting the requirements for clinical diagnosis. In static imaging, four lesions were missed in the LD1 group with a lesion detectability of 89.7% (35/39). In the meantime, lesions were not missed in the whole ultra-low dose group (ULD5, ULD8, ULD10, and ULD15) and half-dose groups (LD2 and LD3).

Conclusions: Compared with half-dose imaging, ultralow-dose [F]FDG total-body PET/CT imaging is clinically feasible, and there was no meaningful difference between the two groups of quantitative and qualitative analysis either dynamic or static images. Total-body PET/CT with ultralow-dose activity, the corresponding acquisition time of 8 min provides acceptable image quality and lesion detection.

Trial Registration: ClinicalTrials.gov identifier: ChiCTR2000036487 KEY POINTS: • A prospective single-center study showed that the total-body PET scanner allows ultralow-dose [F]FDG imaging with acceptable image quality and lesion detectability. • For the participant, radiation exposure can be reduced with ultralow-dose [F]FDG total-body PET/CT imaging.