The study is to evaluate the sstr antagonists, 68Ga-DOTATATE and 177Lu-DOTATATE,as a pair of diagnostic/therapeuticradiopharmaceuticals(theranostics)in patients with NETS
Ability to understand and the willingness to sign a written informed consent document;
Age ≥18 years ;
Low-and medium-grade ( G1 or G2) unresectable locally advanced or metastaticgastrointestinalneuroendocrine tumors(GEP-NETs)confirmed by histopatholog in the central laboratory,and those who had previously progressed after standard-dose somatostatin analogue(SSA)treatment;
Somatostatin receptor positive patients must be defined as all target lesions at baseline confirmed by PET/ CT examination of gallium [68Ga] dobutamine injection as somatostatin receptor positive(IRC confirmed);
Human immunodeficiency virus (HIV) antibody positive;
Hepatitis B virus (HBV) surface antigen (HBsAg) is positive and HBV-DNA is positive (≥the upper limit of detection), or hepatitis C virus (HCV) antibody (HCV-Ab) is positive and HCV-RNA is positive (≥the upper limit of detection));
Pregnant or lactating women;
Received peptide receptor radionuclide therapy (PRRT) before randomization;