The aim of this multicenter, open-label, observational study is to evaluate the safety and efficacy of octreotide microspheres in the treatment of advanced neuroendocrine tumors in real clinical practice, especially to evaluate the treatment of octreotide microspheres in various subgroups of neuroendocrine tumor patients.

Inclusion Criteria:

1. Sign an informed consent form and voluntarily participate in this study;
2. Patients with unresectable or metastatic neuroendocrine tumors confirmed by histopathology. Patients with recurrence and progression after surgery or local treatment can also be included in the study;
3. Age ≥ 18 years old;
4. Treatment with octreotide microspheres.

Exclusion Criteria:

1. Confirmed pregnant or lactating women;
2. Participating in any research with intervention measures outside of routine clinical practice;
3. Other situations unsuitable for inclusion in the study determined by the researcher.

Patients with advanced neuroendocrine tumors treated with octreotide microspheres will be eligible to participate in the study.