Evaluation of the Value of [68Ga]Ga-PENTIXAFOR PET-CT in Patients With Metastatic Small Cell Lung Cancer (SCLC)

Inclusion Criteria: 1. Written informed consent signed before performing any trial specific procedure. 2. Male or female, age ≥ 18 years at time of study entry. 3. Patient with histologically proven small cell lung carcinoma, inoperable, non-pre-treated. 4. Metastatic disease documented by conventional imaging and/or \[18F\]FDG PET-CT with at least one metastatic measurable lesion (RECIST 1.1). Patients eligible for 1st line metastatic treatment. 5. Availability of tissue material (primary lesion and/or metastatic site) to allow additional immunohistochemical studies. 6. PS \< 2. 7. Consent to use a contraception method for at least 3 months after each administration of \[68Ga\]Ga-PentixaFor. 8. Adequate Organ function confirmed by laboratory test results allowing for safe the \[68Ga\]Ga-PentixaFor administration. 9. Life expectancy greater than 3 months. 10. Patient has valid health insurance. 11. Patient willing and able to comply with the protocol throughout the duration of the study, including during treatment and scheduled visits and examinations, including follow-up. Exclusion Criteria: 1. History of cancer in the 3 years prior to entry into the trial other than basal cell carcinoma of the skin or carcinoma in situ of the cervix. 2. History of anti-cancer treatments such as chemotherapy, radiotherapy or immunotherapy as well as other clinical trials for SCLC before the first \[68Ga\]Ga-PentixaFor PET-CT imaging. 3. Inability to lie still for at least 1 hour, or known claustrophobia. 4. Serious non-malignant disease (e.g., psychiatric, infectious, autoimmune, or metabolic) which may interfere with study objectives or patient safety or compliance, in the judgment of the investigator. 5. Unstable diabetes with blood glucose \> 2 g/L. 6. Known hypersensitivity to any active pharmaceutical agent or constituent of the \[68Ga\]Ga-PentixaFor and/or \[18F\]FDG product. 7. Body weight of less than 48 kg. 8. Mental impairment that may compromise the ability to give informed consent and comply with study requirements. 9. Pregnant, likely to be pregnant or breastfeeding woman. 10. Patient deprived of liberty, under judicial safeguard, under curatorship or placed under the authority of a guardian. 11. Disorder preventing understanding of trial information or informed consent.