This is a multicenter, single-arm, two-part study designed to evaluate the safety and efficacy of Lutetium \[177Lu\] Oxyoctreotide Injection in patients with inoperable, locally advanced or metastatic, progressive, advanced somatostatin receptor (SSTR) positive neuroendocrine neoplasms (NEN) other than grade G1/G2 gastroenteropancreatic neuroendocrine tumors (GEP-NET) and Neuroendocrine Carcinoma（NEC）.
Subjects who have been fully informed of this study and have voluntarily signed the Informed Consent Form (ICF).
Age ≥12 years; subjects aged 12-17 years must have a body weight ≥40kg. Age eligibility must be met at the time of signing the ICF.
⁶⁸Ga-Dotatate PET/CT images obtained within 24 weeks before the first drug administration are acceptable if investigators verify they can reflect the somatostatin receptor status at enrollment;
Somatostatin receptor positivity is defined as lesion uptake higher than normal liver uptake;
Serum creatinine > 150 μmol/L (1.7 mg/dL) or creatinine clearance rate < 50 mL/min (calculated by Cockcroft-Gault formula).
Hemoglobin < 100 g/L, white blood cell count < 2.0×10⁹/L, or platelet count < 100×10⁹/L.
Total serum bilirubin > 3 times the upper limit of normal (ULN).
Serum albumin < 30 g/L.