Local Ablative Stereotactic Radiotherapy for Residual Hypermetabolic Lesion in Patients With Locally Advanced or Metastatic Non-small Cell Lung Cancer Long-term Responders to Immunotherapy

Inclusion Criteria: * Patient aged 18 or more, * Patient treated for histologically proven non-small cell lung cancer, * Stage IIIB or IV, * Performance status 0 to 2, * Patient treated by immunotherapy (anti PD-1 or anti PD-L1) started for at least 6 months and regardless of the treatment line (in first line, immunotherapy may have been combined with chemotherapy), * Response or stable disease on thoraco abdomino pelvic and cerebral CT scan, * Maximum 5 residual hypermetabolic lesions measured on the 18F-FDG PET / CT centrally reviewed, including primary tumor and a maximum of 3 asymptomatic brain metastases (even if they are poorly seen in 18F- FDG PET/CT) treatable in stereotactic radiotherapy (extracerebral lesions ≤ 4cm and brain lesions ≤ 3cm measured on CT scanners) * Effective contraception used in women of childbearing potential * Written informed consent obtained from the patient prior to performing any protocol-related procedures, including screening evaluations, * 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, * Patient has valid health insurance. Exclusion Criteria: * Persistence of grade 2 or greater adverse effects of immunotherapy, * Infection in progress, * At least one of the 5 hypermetabolic lesions measured on the 18F-FDG PET / CT centrally reviewed in a previously irradiated area, * Uncontrolled severe comorbidity, * History …