The clinical utility of phase-based respiratory gated PET imaging based on visual feedback with a head-mounted display system

Objective: We developed a new respiratory-gated positron emission tomography (PET) imaging method (RGV-PET) that phase-based respiratory gated PET imaging (RG-PET) combine with head-mounted display (HMD)-guided "visual feedback." The purpose of this study was to investigate whether RGV-PET is effective at improving the quantitative measurement of tracer uptake in tumors using the phase-based respiratory gating method. Methods: Of the 41 enrolled patients with hepatobiliary or pancreatic cancer, 20 patients underwent RGV-PET and the remaining 21 patients underwent RG-PET. We measured the peak standardized uptake value (SUVpeak) of the primary lesion in each five bins obtained from both RG-PET and RGV-PET. The SUVpeak change rate calculated based on the ungated PET imaging. To evaluate the quantitative variation, the coefficient of variation of the SUVpeak change rate was compared between RG-PET and RGV-PET. In addition, we performed qualitative evaluation using visual score for the incidence of artifacts on four-dimensional-CT. Results: The coefficient of variation of the average SUVpeak change rate in RGV-PET was 7.01 +/- 4.43, which was significantly lower than the values in RG-PET (10.72 +/- 5.74, p < 0.05). A significant improvement in the SUVpeak change rate of RGV-PET was obtained in bins 1 and 2 compared to RG-PET (p < 0.05). The visual score of RGV-PET was significantly lower than RG-PET (p < 0.05). Conclusion: RGV-PET was effective for respiratory stabilization and improved respiratory gating imaging quality. Advances in knowledge: The RGV-PET is applicable to various PET/CT respiratory gating imaging and may improve the quantitativeness of PET images.