This study is testing a new way to look at cancer using a special scan called **[68Ga]Ga-FAPI-46 Total Body PET/CT**. PET/CT stands for **Positron Emission Tomography/Computed Tomography**. It's a type of scan that shows detailed pictures of your body. The doctors want to see if this scan can find cancer better and faster, especially in the belly area, for people with *pancreatic* or *gastroesophageal cancer* (cancer of the stomach and esophagus). This study involves three groups of patients: *Group A* with pancreatic cancer, *Group B1* with gastroesophageal cancer needing surgery, and *Group B2* with a specific type of gastroesophageal cancer needing chemotherapy.
- Participants will have one or two special scans and fill out a questionnaire.
- Doctors will check on participants for one year after the scans.
- People must be over 18, not pregnant, and able to read Danish to join.