Investigation of the quarter-dose ¹⁸F-FDG total-body PET in routine clinical practice and its clinical value

Objective The purpose of the study was to evaluate the routine clinical application of total-body PET with quarter-dose F-18-FDG.Methods The contrast recovery coefficient (CRC) and coefficient of variation (COV) were evaluated among full-, half-, and quarter-dose groups with an acquisition duration of 10-, 5-, 3-, and 1-min in the NEMA (IQ) phantom test. Fifty patients undergoing total-body PET/CT with quarter-dose (0.925MBq/kg) of F-18-FDG were included in the prospective study. The acquisition time was 10 min, divided into duration groups of 5-, 3-, and 1-min, referred to as G10, G5, G3, and G1. Visual scores were assessed based on overall visual assessment, noise scoring, and lesion conspicuity. Lesion SUVmax and TBR were evaluated in semi-quantitative analysis. G10 was used as the gold reference to evaluate lesion detectability.ResultsIn the phantom study, the COV value of the images with quarter-dose F-18-FDG and 10-min acquisition time was 11.52%. For spheres with 10 mm diameter, the CRC of quarter-dose PET images was relatively stable compared to that of full-dose groups with all acquisition durations. In the human study, the visual score in G10, G5, and G3 was significantly higher than that in G1. The differences in lesion SUVmax and TBR for G1-G10 were significantly higher than that for G5-G10 and G3-G10. All lesions in G10 could be identified in G5 and G3.Conclusion The phantom and human findings demonstrated the feasibility of quarter-dose F-18-FDG PET with 3-min acquisition time, which can maintain image quality with reduced radiation dose.