Intra-arterial Hepatic (IAH) Infusion of Radiolabelled Somatostatin Analogs in GEP-NET Patients With Dominant Liver Metastases

Inclusion Criteria: * Histologically proven well differentiated neuroendocrine tumor (NET) of gastrointestinal or pancreatic origin (GEP). * Patients are progressive after treatment with cold somatostatin analog (within 12 months according to RECIST), or as soon as the diagnosis is made in case of hepatic invasion \> 50% without waiting for tumour progression * Patient has received 4 standard of care LUTATHERA® cycles * Liver Metastatic disease dominant or exclusive and assessable by RECIST 1.1, and not amenable to surgical resection after the last cycle * ECOG performance status 0-2 * Adequate kidney and liver function: creatinine clearance ≥ 50 mL/min, ALT/AST ≤ 2,5x the upper limit of normal * With no evidence of hematologic alteration after 4 LUTATHERA® cycles: hemoglobin ≥ 8 g/dL, neutrophils ≥ 1500/ mm3, platelets ≥ 75.000/mm3 * Age ≥ 18 years, no superior limit * Contraception required in pre-menopausal female (Intrauterine device, Progestin Pills, Combined Oral Contraceptives, Monthly Injectables, Progestin Injectables, Combined Patch, Combined Vaginal Ring, Female Sterilization, Vasectomy, Implants) and men for at least 6 months after the last LUTATHERA ® injection. * Patient´s signed written informed consent * Patient affiliated to a social security system Exclusion Criteria: * Patients with complete response defined by the absence of lesion according to RECIST 1.1 realized during morphological imaging at inclusion (chest-abdomen-pelvis CT scan and hepatic MRI) * No residual uptake according to standard 177-Lu scintigraphy performed in the clinical routine 24 hours after each LUTATHERA IV treatment * Carcinoid heart disease (LVEF \< 40%) * Dominant or threatening extrahepatic metastases or that may affect vital prognosis * Contraindications to intra-hepatic arterial infusion (coagulation disorders, portal thrombosis, intra-hepatic biliary tract dilatation, digestive or biliary anastomosis or fistula, cirrhosis (Child Pugh B8 or C…) * Serum albumin \<30 g/L unless prothrombin time is within the normal range. * Heart failure, myocardial infarction, stroke, uncontrolled arterial hypertension under optimal treatment (≥ 160/95 mmHg), pulmonary embolism or revascularization procedure, unstable angina pectoris, uncontrolled cardiac arrhythmia, and clinically significant bradycardia during the last 12 months. * Individuals under legal protection or unable of giving their informed consent * Pregnancy or breast feeding * Currently participating to another clinical research protocol * Individuals under legal protection or unable of giving their informed consent * MRI scan contraindicated * LUTATHERA® contraindicated or toxicity during one of the IV administrations leading to a reduction or cancellation of the following dose