Consolidation Radiotherapy vs. Observation in Oligoresidual Advanced Non-Small Cell Lung Cancer After Chemo-Immunotherapy

The purpose of this clinical study is to find out whether the addition of local radiation therapy (radiotherapy) after standard chemotherapy and immunotherapy is better than continuing maintenance therapy alone for patients with specific types of advanced lung cancer . Study Objectives and Hypotheses: The primary objective is to see if the addition of radiation therapy to target residual lesions will prolong the time that a patient's cancer does not get worse (progression-free survival) in patients with advanced non-small cell lung cancer (NSCLC) who have a limited number of tumors (known as "oligo-residual lesions") after receiving first-line chemotherapy in combination with immunotherapy . The researchers hypothesized that patients who receive maintenance therapy plus radiation therapy will have their cancer progress more slowly than patients who receive only maintenance therapy . Study Population: This study is for adult patients 18 years of age and older who have been diagnosed with advanced non-small cell lung cancer . These patients have received 4 to 6 cycles of first-line chemotherapy in combination with immunotherapy and have a limited number of tumor lesions on post-treatment imaging (PET-CT) (no more than 5 residual lesions involving no more than 3 organs) and no specific genetic mutations (e.g., Epidermal Growth Factor Receptor \[EGFR\], Anaplastic Lymphoma Kinase \[ALK\], etc.). Study Methods: Eligible patients will be randomly assigned to one of two groups : Experimental group: continuation of maintenance therapy (either immunotherapy or chemotherapy combined with immunotherapy, depending on the previous regimen) and local radiotherapy to all residual tumor lesions. Control group: Continuation of maintenance therapy only. Key questions to be answered by the study: Primary question: is the addition of local radiotherapy more effective in slowing cancer progression than maintenance therapy alone in this group of lung cancer patients? Secondary questions include: Does the addition of radiotherapy prolong overall survival? How effective is it in controlling residual disease? What is the safety (side effects) of the treatment and how does it affect the patient's quality of life? What participants need to do: Be randomized to one of the treatment groups . Receive the appropriate treatment (maintenance therapy, or maintenance therapy plus radiotherapy) according to their group. Have regular check-ups and imaging scans to assess the status of the tumor. Complete questionnaires about quality of life. May be asked to provide a blood sample for research . This study will help doctors to better understand how to treat this special group of patients with advanced lung cancer, with a view to improving their outcome and quality of life.