The investigators will number all participants, create a medical record file, and record their basic information (gender, age) as well as contact information and medical history information. One or two \[68Ga\]Ga-NODAGA-SNA014 PET scans will be performed according to disease stage and treatment plan. CLDN18.2 expression will be assessed by immunohistochemistry (IHC) in surgical specimens. The optimal SUV threshold and PET quantification potential for CLDN18.2 expression will be evaluated in comparison with histopathology, along with their correlation with prognosis.
