Assessement of Potential Interest of [68Ga]Ga-PentixaFor PET/CT in Metastatic Triple Negative Breast Cancer Patients

Inclusion Criteria:

1. Written informed consent obtained from the patient prior to performing any protocol-related procedures, including screening evaluations.
2. Female or male, Age ≥ 18 years at time of study entry.
3. Primitive triple negative breast cancer proven histologically, defined according to the following criteria:

   * Estrogen receptors \<10%.
   * And progesterone receptors \<10%.
   * And HER2 not amplified or not overexpressed.
4. Recurrence metastatic Breast Cancer or De Novo metastatic Breast Cancer documented by \[18F\]FDG PET/CT ± conventional imaging with at least one measurable metastasis according to PERCIST and/or RECIST.
5. ECOG performance status \< 2.
6. Negative serum/urine pregnancy test prior to \[68Ga\]Ga-PentixaFor administration for female patient of childbearing potential\*.
7. Consent to use a contraception method for at least 3 months after each administration of \[68Ga\]Ga-PentixaFor (as defined in Appendix 7 and according to local guidelines).
8. Adequate Organ function confirmed by laboratory tests results allowing for safe administration of \[68Ga\]Ga- PentixaFor:

   Hematologic function: Absolute Neutrophil Count (ANC) of ≥ 1.5 x 109 /L, platelet count of ≥ 100 x 109 /L, and hemoglobin of ≥ 9 g/dL).

   Hepatic function: AST and ALT ≤ 3 x ULN (≤ 5 x ULN if liver metastases).
9. Renal function: Estimated Glomerular Filtration Rate (eGFR) ≥ 50 mL/min/1.73m², as calculated using the CKD-EPI or MDRD equation.Life expectancy at least 3 months.
10. Patient has valid health insurance.
11. Patient is willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations including follow up.

    * Note: a female participant of childbearing potential is a woman who is not permanently sterilized or not postmenopausal (postmenopausal is defined as 12 months with no menses without an alternative medical cause).

Exclusion Criteria:

1. History of another primary malignancy within the last 3 years before study entry except for basal cell carcinoma.
2. Impossibility to hold lying motionless at least 1 hour, or known claustrophobia.
3. Serious non-malignant disease (e.g. psychiatric, infectious, autoimmune or metabolic), that may interfere with the objectives of the study or with the safety or compliance of the subject, as judged by the investigator.
4. Mental impairment that may compromise the ability to give informed consent and comply with the requirements of the study.
5. Pregnant, likely to be pregnant or breastfeeding woman.
6. Blood glucose \> 12mmol/L.
7. Renal insufficiency with GFR ≤ 45 mL/min/ 1.73 m².
8. Known hypersensitivity to any active pharmaceutical agent or constituent of the \[68Ga\]Ga-PentixaFor and/or \[18F\]FDG product.
9. Body weight of less than 48 kg.
10. Persons deprived of their liberty, under a measure of safeguard of justice, under guardianship or placed under the authority of a guardian.
11. Disorder precluding understanding of trial information or informed consent.