In this project, based on the DTPA-HAS kit, investigators plan to develop a positron nuclide 68Ga labeled DTPA-HSA molecular probe in order to obtain high sensitivity, signal-to-noise ratio and high-resolution PET/CT imaging images, aiming to find the specific site of intestinal leakage while diagnosing Protein-Losing Enteropathy (PLE), and analyze the pathological mechanism of intestinal leakage in combination with pathology, so as to provide molecular imaging guidance for the treatment of PLE patients. PLE is a rare gastrointestinal protein-losing syndrome, and the radiopharmaceutical 99mTc-DTPA-HSA (99mTc-human serum albumin) approved by the State Food and Drug Administration has the diagnostic ability of protein-losing enteropathy (PLE), but due to the low resolution of SPECT/CT, the image clarity and signal-to-noise ratio need to be improved, it is a classic probe in the last century, unable to meet the existing clinical needs.

This project developed a a new type of nuclide Ga-68 labeled DTPA-HSA probe, and with the inherent advantages of this nuclear medicine department, it has promoted the formulation of the production filing standard of the drug, and obtained the 68Ga-HSA injection that can be used for preclinical research and meets the clinical standards. Clinical research on 68Ga-HSA PET/CT imaging was carried out to provide a basis for the diagnosis and treatment of PLE patients.

Inclusion Criteria:

1. Patients with digestive system tumors;
2. Presence of hypoproteinemia or clinical manifestations of hypoplasma protein;
3. Serum albumin <30 g/L, AAT>80 ml/d;
4. Measurable lesions in imaging;
5. Predicted survival greater than 3 months;

Exclusion Criteria:

1. Severe hepatic or renal dysfunction;
2. Pregnant or nursing;
3. Known allergy to the investigational drug or its excipients in study;
4. Unable to comply with the PET/CT imaging procedures;
5. Claustrophobia or other psychiatric disorders;
6. Other conditions deemed unsuitable for participation in the trial;

Patients at Being Cancer Hospital who are confirmed protein-losing enteropathy, or digestive system tumors with hypoproteinemia.