Objective:To systematically evaluate the safety and efficacy of the novel fibroblast activation protein (FAP)-targeted tracer 64Cu-FAP inhibitor (FAPI)-XT117 in patients with malignant solid tumors, and to compare with 18F-FDG. Methods:This self-controlled study was conducted on fifteen patients (8 males, 7 females; age (60 ±9) years) with malignant solid tumors from the First Affiliated Hospital of Guangzhou Medical University between July 2023 and December 2023. Each subject underwent 64Cu-FAPI-XT117 PET/CT at 30, 60, and 120min post-injection and was assigned to three dose cohorts (111MBq, 148MBq, and 185MBq; 5 patients in each cohort), and safety assessments were conducted within 24h after injection. In addition, all patients underwent 18F-FDG PET/CT at 60min post-injection. Time-activity curves were generated for 64Cu-FAPI-XT117, and the dosimetry was calculated. Image quality was evaluated using a 5-point Likert scale, and the optimal injected activity and imaging time point were determined. The paired t test was used to compare differences of the lesion detection count and SUV max between 64Cu-FAPI-XT117 and 18F-FDG PET/CT. Results:64Cu-FAPI-XT117 was well tolerated, with no adverse events reported. Time-activity curves of 68Ga-FAPI-XT117 revealed prominent uptake in the uterus, while the background activity in other organs remained low, with the whole-body effective dose of (0.0084±0.0021)mSv/MBq. The optimal imaging time point for 64Cu-FAPI-XT117 PET/CT was 60min post-injection, with an optimal administered activity of 111MBq. Compared with 18F-FDG, 64Cu-FAPI-XT117 demonstrated significantly higher uptake and more lesions in lymph-node metastases (SUV max: 8.6±3.8 vs 15.3±6.8, t=2.33, P=0.048; number of lesions: 8.3±5.4 vs 15.0±6.4; t=4.21, P=0.003) and distant metastases (SUV max: 11.8±3.7 vs 20.9±7.2, t=3.66, P=0.022; number of lesions: 7.0±3.2 vs 12.4±3.7, t=2.86, P=0.046). Conclusions:64Cu-FAPI-XT117 PET/CT is well tolerated in patients with solid tumors, with a controllable radiation risk. Moreover, it outperforms 18F-FDG PET/CT in the assessment of metastases.

Objective:To systematically evaluate the safety and efficacy of the novel fibroblast activation protein (FAP)-targeted tracer 64Cu-FAP inhibitor (FAPI)-XT117 in patients with malignant solid tumors, and to compare with 18F-FDG. Methods:This self-controlled study was conducted on fifteen patients (8 males, 7 females; age (60 ±9) years) with malignant solid tumors from the First Affiliated Hospital of Guangzhou Medical University between July 2023 and December 2023. Each subject underwent 64Cu-FAPI-XT117 PET/CT at 30, 60, and 120min post-injection and was assigned to three dose cohorts (111MBq, 148MBq, and 185MBq; 5 patients in each cohort), and safety assessments were conducted within 24h after injection. In addition, all patients underwent 18F-FDG PET/CT at 60min post-injection. Time-activity curves were generated for 64Cu-FAPI-XT117, and the dosimetry was calculated. Image quality was evaluated using a 5-point Likert scale, and the optimal injected activity and imaging time point were determined. The paired t test was used to compare differences of the lesion detection count and SUV max between 64Cu-FAPI-XT117 and 18F-FDG PET/CT. Results:64Cu-FAPI-XT117 was well tolerated, with no adverse events reported. Time-activity curves of 68Ga-FAPI-XT117 revealed prominent uptake in the uterus, while the background activity in other organs remained low, with the whole-body effective dose of (0.0084±0.0021)mSv/MBq. The optimal imaging time point for 64Cu-FAPI-XT117 PET/CT was 60min post-injection, with an optimal administered activity of 111MBq. Compared with 18F-FDG, 64Cu-FAPI-XT117 demonstrated significantly higher uptake and more lesions in lymph-node metastases (SUV max: 8.6±3.8 vs 15.3±6.8, t=2.33, P=0.048; number of lesions: 8.3±5.4 vs 15.0±6.4; t=4.21, P=0.003) and distant metastases (SUV max: 11.8±3.7 vs 20.9±7.2, t=3.66, P=0.022; number of lesions: 7.0±3.2 vs 12.4±3.7, t=2.86, P=0.046). Conclusions:64Cu-FAPI-XT117 PET/CT is well tolerated in patients with solid tumors, with a controllable radiation risk. Moreover, it outperforms 18F-FDG PET/CT in the assessment of metastases.

Objective To evaluate the changes of adenosine metabolism pathway related molecules and their contribution to inflammatory injury in primary biliary cholangitis (PBC).Methods The consecutive samples of 49 subjects with PBC from The First People's Hospital of Taicang and The Second People's Hospital of Changshu were recruited from October 2016 to October 2017,and 36 healthy controls were involved in this study.The expression of CD39 and CD73 on CD4+T cells and Foxp3 + regulatory T cells were assayed by flow cytometry and the concentration of adenosine triphosphate (ATP) in serum was analyzed by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS).The correlations between Tregs,ATP and liver function were analyzed,i.e.,alanine aminotransferase (ALT),aspartate aminotransferase (AST),gamma-glutamyltransferase (GGT),alkaline phosphatase (ALP) and Mayo scores.Results In the patients with PBC,low proportions of CD4+CD39+T cells were noted compared with healthy controls [(5.28 ± 1.92) ％ vs (11.0l ± 3.19) ％,t =10.25,P ＜ 0.01].The patients with PBC also had significantly low proportion of CD4+CD25 + Foxp3+ CD39+ T cells compared with healthy controls [(23.75 ± 9.48) ％ vs (54.68 ± 5.18) ％,t =13.79,P ＜0.01].No significant difference of the proportion of CD4+CD73+T or CD4+CD25+ Foxp3+CD39+T cells was found between PBC and control groups (t values were 2.235 and 1.083,P ＞ 0.05).The level of serum ATP was higher in the patients with PBC than that of healthy controls [(200.28 ± 79.41) μg/L vs (89.20 ± 33.76) μg/L,t =8.367,P ＜ 0.01].A significant correlation was demonstrated between the proportion of CD39 + Treg in total Treg cells and the levels of ATP (r =-0.413,P =0.003),GGT (r=-0.378,P=0.007) and Mayo score (r=-0.382,P=0.007).Conclusion The low proportion of CD39+ Treg cells may contribute to the down-regulation of ATP hydrolysis in the patients with PBC.No significant change of CD73 + Treg cells was found in PBC patients.