PET/CT with 68Ga-FAPI and 18F-FDG in the Detection of Distant Metastases of Gastric Cancer

Purpose : To determine the diagnostic effectiveness of PET/CT with 68 Ga-FAPI in the detection and staging of metastases in patients with gastric cancer. Material and methods : The study included 57 patients with histologically confirmed gastric cancer. All patients underwent PET/CT with 68 Ga-FAPI and PET/CT with 18 F-FDG. The diagnostic accuracy of the methods was compared based on sensitivity and specificity parameters in detecting distant metastatic lesions. Data assessment was conducted based on histologically verified disease and clinical follow-up data. Results : 57 patients underwent both 68 Ga-FAPI PET/CT and 18 F-FDG PET/CT. In 5 patients (8.7 %), the treatment plan was changed from radical to palliative based on the 68Ga-FAPI PET/CT results. 68 Ga-FAPI PET/CT detected distant metastases in 29 patients (50.8 %), while with 18 F-FDG, distant metastases were detected in 18 patients (31.5 %). The sensitivity of 68 Ga-FAPI PET/CT in detecting distant metastases was 100 %, with a specificity of 85.7 %, whereas for 18 F-FDG, these values were 62 % and 90 %, respectively. Conclusion : PET/CT with 68 Ga-FAPI is a more effective diagnostic method for detecting distant metastases of gastric cancer than PET/ CT with 18 F-FDG. The obtained results indicate the need to use PET/CT with 68 Ga-FAPI in clinical practice for more accurate diagnosis and treatment strategy selection in gastric cancer.