The Evaluation of Pediatric Malignancies Using Total-body PET/CT With Half Dose 18F-FDG

作者：Wan-Qi Chen, Lei Liu, Ying‐He Li, Shatong Li, Zhijian Li, Weiguang Zhang, Xu Zhang, De-bin Hu, Hongyan Sun, Yun Zhou, Wei Fan, Yumo Zhao, Yizhuo Zhang, Yingying Hu · 发表于：Research Square · 年份：2022 · DOI：10.21203/rs.3.rs-1444072/v1 · 被引用次数：2 · 研究领域：Medical Imaging Techniques and Applications、Advanced Radiotherapy Techniques、Radiation Dose and Imaging

Abstract Purpose To explore the effect of half 18 F-FDG dose on image quality of pediatric oncological patients using total-body PET/CT. and investigate the ultra-low dose of administered tracer activity. Methods 100 pediatric oncological patients who underwent total-body PET/CT using the uEXPLORER scanner with half 18 F-FDG dose (1.85 MBq/kg) were retrospectively enrolled. The PET images were firstly reconstructed using all the 600s data, and then split into 300s, 180s, 60s, 40s and 20s duration groups. The subjective analysis method was assessed using a 5-point Likert scales. Objective quantitative metrics included the maximum standard uptake value (SUV max ), SUV mean , standard deviation (SD), signal to noise ratio (SNR) and SNR norm of the backgrounds. The variability in lesion SUV mean , SUV max , and tumor-to-background ratio (TBR) were also calculated. Results The overall image quality scores in Group 600s, 300s, 180s and 60s were 4.9 ± 0.2, 4.9 ± 0.3, 4.4±0.5 and 3.5±0.5 respectively. All the lesions identified in half-dose images were localised down to G60s (1/20-dose) images; while 56% of the lesion could be clearly identified in G20s (1/60-dose) images. With stimulated reduced doses, SUV max and SD of backgrounds were gradually increased, while TBR values showed no statistically significant deviation among all the groups (all p > 0.1). Using the half-dose images as reference, the variability of lesion SUV max gradually increased from G180s to G20s, while lesion...