Inclusion Criteria:  Patients aged ≥ 18 years. Histologically confirmed diagnosis of unresectable, well-differentiated GastroEnteroPancreatic NeuroEndocrine Tumors (GEP-NETs). measurable site of disease per RECIST v1.1 (Response evaluation criteria in solid tumors) using contrast computed tomography (CT) / magnetic resonance imaging (MRI). Somatostatin receptor-positive (SSTR+) disease.  Exclusion Criteria:  Known hypersensitivity to Lutetium 177Lu, edotreotide, DOTA (dodecane tetraacetic acid), any of the comparators, or any excipient or derivative (e.g. rapamycin). Prior (Peptide Receptor Radionuclide Therapy) PRRT. Any major surgery within 4 weeks prior to randomization in the trial. Therapy with an investigational compound and/or medical device within 30 days or 7 half-life periods (whichever is longer) prior to randomization. Other known malignancies. Serious non-malignant disease. Renal, hepatic, cardiovascular, or hematological organ dysfunction, potentially interfering with the safety of the trial treatments. Pregnant or breastfeeding women. Patients not able to declare meaningful informed consent on their own or any other vulnerable population to that.