Evaluate the Diagnostic Efficacy, Pharmacokinetics and Safety of 68Ga-DOTATATE Injection PET/CT in NETs

Inclusion Criteria: 1. Age \> 18 years old, no gender limit; 2. Karnofsky status score \>50 points; 3. Expected survival time \>3 months; 4. Those who have a history of neuroendocrine tumors,but require PET/CT examination for structure, location and function evaluation and disease management, and have measurable lesions; CT, MRI, 18F-FDG PET/CT or other imaging examinations are suspected of being NETs or those with space-occupying lesions and at least one of the following: ① Biochemical and tumor biomarkers results of blood or urine suggest that the subject is suspected of suffering from NETs (chromogranin A,neurospecific enolase,vasoactive intestinal peptide, serotonin (urinary 5-HIAA), gastrin, somatostatin,catecholamines,calcitonin,fasting insulin,C-Peptides(proinsulin) orglucagon abnormal biochemical indicators related to neuroen docrine tumors); ②Multiple endocrine neoplasia type 1 (MEN1) and Lindau syndrome (VHL) with familial tendency to be susceptible to NETs (symptomatic and/or asymptomatic cases; with biochemical or anatomical imaging evidence of the disease); 5. The subjects or their guardians fully understand the content,process and possible risks of the trial and voluntarily sign the informed consent form. Exclusion Criteria: 1. Known to be allergic to any components or excipients of 68Ga-DOTATATE injection; 2. Unable to remain relatively still during the imaging examination (such as coughing, severe arthritis, etc.), or body shape and/or weight exceeds the applicable range of the examination equipment; 3. Unable to complete the imaging examination specified in the plan due to claustrophobia,radiation phobia or personal wishes; 4. With a history of concurrent active infection or severe heart disease; 5. Those who have used long-acting somatostatin analogs within 28 days or short-acting somatostatin analogs within 2 days before the scheduled PET/CT examination of 68Ga-DOTATATE injection; 6. Those who receive long-term and repeated treatment with high-dose glucocorticoids; 7. Pregnant or lactating women,or those who do not agree to take effective contraceptive measures from the date of signing the informed consent form to 3 months after administration; 8. Blood test results a) WBC: \< 2 x 109/L, b) Haemoglobin:\< 8.0 g/dL, c) Platelets: s 50 x 109/L, d) ALT. AST. AP:\> 5 times ULN, e) Bilirubin:\> 3 times ULN, f) Serum creatinine:\> 1.5 times ULN 9. Those who have participated in other interventional clinical trials or are participating in other interventional clinical trials within 1 month or 5 drug half-lives( whichever is longer ) before the date of signing the informed consent,or have participated in clinical trials of radioactive drugs within 1 year before the date of signing the informed consent, and the withdrawal time is less than 3 months until the date of signing the informed consent; 10. Investigators considered unsuitable to participate in this trial.