Feasibility of one-tenth dose 18F-FDG total-body PET/CT in patients with malignant tumors / 中华核医学与分子影像杂志

ABSTRACT

Objective:To explore the feasibility of one-tenth dose 18F-FDG total-body PET/CT (TB PET/CT) in patients with malignant tumors. Methods:A retrospective analysis was carried out on 34 preliminarily diagnosed cancer patients (30 males, 4 females, age (64.0±1.6) years) who underwent one-tenth dose (0.37 MBq/kg) 18F-FDG TB PET/CT examination between April 2020 and September 2022 in Zhongshan Hospital, Fudan University. The raw data were reconstructed into 15 min and initial 2 min PET images (G15 and G2, respectively). A matched cohort of 34 preliminarily diagnosed malignant tumor patients (27 males, 7 females, age (63.3±2.1) years) undergoing full dose (3.70 MBq/kg) 18F-FDG conventional digital PET/CT (C PET/CT) examination with a PET scan rate of 2-3 min/bed position, were analyzed in line with the same pathological types. Signal-to-noise ratios (SNR) of G15, G2 and C PET/CT groups were compared, and based on the pathological results, the detection rates of those 3 groups for lesions were also compared. The χ2 test, independent sample t-test, Mann-Whitney U test, and Wilcoxon rank sum test were used for data analysis. Results:The significant differences in gender, age, body mass index (BMI), blood sugar level and postinjection waiting time between TB PET/CT group and C PET/CT group were not found ( χ2=0.98, t values: 0.08, -1.05, z values: 0.68, 0.41, all P>0.05). The SNR, from G15 to C PET and G2 groups, decreased gradually, which were 16.0(11.3, 20.0), 10.5(8.2, 13.5) and 8.4±0.3 respectively ( z values: 5.09, 3.31, -4.24, all P<0.05). All primary lesions and hepatic metastases were detected by G15 and G2 imaging (100%, 37/37) as well as by C PET/CT (100%, 36/36). The detection rates for lymph node metastasis lesions were 10/15 in the G2/G15 groups, which were higher than the detection rate in the C PET/CT group (64.4%(29/45); χ2=62.03, P=0.002). Conclusion:One-tenth dose 18F-FDG TB PET/CT with a 2-minute acquisition is feasibility in the clinical practice.