Precision medicine represents a major goal in oncology. It has its underpinning in the identification of biomarkers with diagnostic, prognostic, or predictive values. Gastro-entero-pancreatic neuroendocrine neoplasia (GEP-NENs) are rare tumors, but their frequency is increasing. In this context, the tumor expression of carbonic anhydrase IX (CAIX), complemented by a restricted profile in normal tissues, provides an opportunity for therapeutic targeting and precision medicine. Indeed, radiolabeling the anti-CAIX monoclonal antibody girentuximab with Zirconium 89 has shown promise as a novel positron emission tomography (PET) tracer and labeling with 177 Lutetium promise as a therapeutic agent in clear cell renal cell carcinoma (ccRCC) in the context of a theranostic approach. The purpose of this study is to evaluate the use of 89Zr-labeled girentuximab (89Zr-TLX250) as a novel, carbonic anhydrase IX (CAIX) targeted PET/CT tracer for the imaging of Gastro-Entero-Pancreatic Neuroendocrine Neoplasms, Hepatocellular Carcinoma or IntraHepatic Cholangiocarcinoma.

Inclusion Criteria:

1. Provided written informed consent.

2. Patients aged ≥ 18 years.

3. - For basket 1 and 2: HCC or ICC histologically proven: newly diagnosed patients or patients with suspected refractory, residual, or recurrent disease.

   - For basket 3: Progressive GEP-NENs with low or heterogeneous expression of SSTR2 or progressive pancreatic NENs which previously received at least two systemic treatments (excluding SSA) or pancreatic NENs with germline or somatic VHL mutation or G3 GEP-NENs .

4. Presence of at least one morphological evaluable lesion according to RECIST 1.1 using contrast CT/MRI.

5. Patients must have an ECOG (Eastern Cooperative Oncology Group) performance status of 0 to 2.

6. For cirrhotic patients: Child-Pugh ≤ B7.

7. Patient affiliated to or beneficiary of the National Health Service.

Exclusion Criteria:

1. Known hypersensitivity to zirconium-89, to any excipient or derivative or to radiographic contrast agents.
2. Chemotherapy, extensive external beam radiation, immunotherapy, targeted therapy, or angiogenesis inhibitors within 2 weeks prior to 89Zr-TLX250 administration.
3. Radionucleide targeted therapy prior to inclusion within 3 months prior to inclusion.
4. Radioembolization within 3 months prior to inclusion.
5. Uncontrolled brain or spinal cord metastasis.
6. Cardiac disease with New York Heart Association classification of III or IV.
7. Life expectancy shorter than 4 months.
8. Any major surgery within 4 weeks before enrollment.
9. Any uncontrolled significant medical, psychiatric or surgical condition (active infection (subjects with known human immunodeficiency virus (HIV) positive)), unstable angina pectoris, cardiac arrhythmia, poorly controlled hypertension, poorly controlled diabetes mellitus (glycated haemoglobin (HbA1c) ≥9%), uncontrolled congestive heart disease, etc.) or laboratory findings that, in the opinion of the investigator, might jeopardise the subject's safety or that would limit compliance with the objectives and assessments of the study.
10. Other known malignancies (except for fully-resected non-melanoma skin cancer or cervical cancer in situ) unless definitively treated and proven no evidence of recurrence for 2 years.
11. Women who are pregnant or breastfeeding. A serum pregnancy test will be performed at the start of the study for all female subjects of childbearing potential.
12. Patient under guardianship or trusteeship.
13. Patient under judicial protection.