68 Ga-conjugated fibroblast activation protein inhibitor ( 68 Ga-FAPI) has become an attractive agent for positron emission tomography (PET). This study aimed to compare 68 Ga-FAPI-46 PET/computed tomography (CT) with 18 F-fluorodeoxy-D-glucose ( 18 F-FDG) PET/CT for detecting primary cancer and metastatic lesions in patients with head and neck squamous cell carcinoma (HNSCC).Methods: Twelve patients and twenty-eight patients with HNSCC underwent 68 Ga-FAPI-46 and 18 F-FDG PET/CT for initial staging and recurrence detection, respectively. Concordance and diagnostic accuracy of both tracers were analyzed. Semiquantitative parameters, including the maximum and mean of standardized uptake value (SUVmax and SUVmean) and tumor-tobackground ratio (T/B) were compared. FAP expression tumor volume (FTV) and total lesion FAP expression (TLF) of 68 Ga-FAPI-46 were compared with metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of 18 F-FDG, respectively. Differences between semiquantitative parameters were analyzed using paired t-tests.Results: 68 Ga-FAPI -46 PET/CT was 83.3% and 96.4% concordant with 18 F-FDG PET/CT for initial staging and recurrence detection, respectively. Eighteen lesions had histopathological validation and both tracers displayed 100% sensitivity, 50% specificity, and 94.4% accuracy for lesion-based analysis. FTV was greater than MTV (P < 0.05), but no significant differences were observed for the other parameters. Conclusion:68 Ga-FAPI-46 PET/CT showed good concordance and comparable diagnostic performance compared with 18 F-FDG PET/CT for initial staging and recurrence detection in patients with HNSCC.
Purpose To compare quantitative parameters and tumour detection rates of [ 68 Ga]Ga-FAPI PET/CT with those of dedicated liver PET/MRI and 18 F-FDG PET in patients with liver malignancies. Procedures Twenty-seven patients (29 imaging studies) with diagnosed or suspected liver malignancies who underwent [ 68 Ga]Ga-FAPI-46 PET/CT, liver PET/MRI, and [ 18 F]FDG PET/CT between September 2020 and June 2021 were retrospectively analysed. MRI findings were used as the reference standard for diagnosis. Results The 27 patients had a median age of 68 years (interquartile range: 60–74 years; 21 men). Primary intrahepatic tumours were reported in 13 patients (15 imaging studies) with cholangiocarcinoma (CCA) and in 14 patients with hepatocellular carcinoma (HCC). All intrahepatic lesions detectable on MRI were also detected on [ 68 Ga]Ga-FAPI-46 PET/CT giving a sensitivity of 100% (19/19), whereas the sensitivity of [ 18 F]FDG PET/CT was 58% (11/19). All intrahepatic lesions were detected on [ 68 Ga]Ga-FAPI-46 PET/CT, on which they showed higher activity (median SUVmax: 15.61 vs. 5.17; P < .001) and higher target-to-background ratio (TBR; median, 15.90 vs. 1.69, P < .001) than on [ 18 F]FDG, especially in patients with CCA (median TBR, 21.08 vs. 1.47, respectively; P < .001). The uptake positivity rate in regional node metastasis was 100% (12/12) on [ 68 Ga]Ga-FAPI-46 PET/CT compared with 58% (7/12) on [ 18 F]FDG PET/CT. All patients with distant metastasis (100%, 14/14) were detected on both [ 18 F]FDG and [ 68 Ga]Ga-FAPI-46 PET/CT imaging, although more distant metastatic lesions were detected on [ 68 Ga]Ga-FAPI-46 PET/CT than on [ 18 F]FDG (96% (42/44) vs. 89% (39/44), respectively). Conclusion [ 68 Ga]Ga-FAPI PET/CT with dedicated liver PET/MRI shows potential for superior detection of hepatic malignancy compared with [ 18 F]FDG PET/CT or MRI alone. Supplementary Information The online version contains supplementary material available at 10.1007/s11307-022-01732-2.
Background: The study aimed to evaluate the appropriate uptake-timing in cognitively normal individuals, mild cognitive impairment (MCI), and Alzheimer’s disease (AD) patients, using 18F-PI 2620 dynamic PET acquisition. Methods: Thirty-four MCI patients, 6 AD patients, and 24 cognitively normal individuals were enrolled in this study. A dynamic 18F-PI 2620 PET study was conducted at 30-75 minutes post-injection in these groups. Co-registration was applied between the dynamic acquisition PET and T1-weighted MRI to delineate various cortical regions. The standardized uptake value ratio (SUVR) was used for quantitative analysis. P-mod software with the Automated Anatomical Labeling (AAL)-merged atlas was employed to generate automatic volumes of interest for 11 brain regions. Results: The curves in most brain regions presented an average SUVR stability at 30-40 minutes post-injection in each group. The appropriate uptake-timing interval of 18F-PI 2620 was 30-75 minutes post injection for AD group and 30-40 minutes post injection for both cognitively normal individuals and MCI groups. Conclusion: Short uptake time around 30-40 minutes post-injection would be more comfortable and convenient for all patients, especially in those with dementia who were unable to stay motionless for long periods of scanning time in the scanner.
Background. Some studies have reported the effectiveness of [18F]PI-2620 as an effective tau-binding radiotracer; however, few reports have applied semiquantitative analysis to the tracer. Therefore, this study’s aim was to perform a semiquantitative analysis of [18F]PI-2620 in individuals with normal cognition and patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Methods. Twenty-six cognitively normal (CN) subjects, 7 patients with AD, and 36 patients with MCI were enrolled. A dynamic positron emission tomography (PET) scan was performed 30–75 min postinjection. PET and T1-weighted magnetic resonance imaging scans were coregistered. The standardized uptake value ratio (SUVr) was used for semiquantitative analysis. The P-Mod software was applied to create volumes of interest. The ANOVA and post hoc Tukey HSD were used for statistical analysis. Results. In the AD group, the occipital lobe had a significantly higher mean SUVr ( 1.46 ± 0.57 ) than in the CN and MCI groups. Compared with the CN group, the AD group showed significantly higher mean SUVr in the fusiform gyrus ( 1.06 ± 0.09 vs. 1.49 ± 0.86 ), inferior temporal ( 1.07 ± 0.07 vs. 1.46 ± 0.08 ), parietal lobe, lingual gyrus, and precuneus regions. Similarly, the AD group demonstrated a higher mean SUVr than the MCI group in the precuneus, lingual, inferior temporal, fusiform, supramarginal, orbitofrontal, and superior temporal regions. The remaining observed regions, including the striatum, basal ganglia, thalamus, and white matter, showed a low SUVr across all groups with no statistically significant differences. Conclusion. A significantly higher mean SUVr of [18F]PI-2620 was observed in the AD group; a significant area of the brain in the AD group demonstrated tau protein deposit in concordance with Braak Stages III–V, providing useful information to differentiate AD from CN and MCI. Moreover, the low SUVr in the deep striatum and thalamus could be useful for excluding primary tauopathies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.