Effect of Low-dose Radiotherapy on Tumor Immune Microenvironment in Oligometastases of NSCLC After Immunotherapy

Inclusion Criteria

• •1. Agree to take pathologic biopsies of oligometastasis, oligoprogression, or oligopersistence lesions before and up to 24h after LDRT. And be willing and able to provide written informed consent/assent for the trial.
• •2. Patients with histologically or cytologically confirmed NSCLC.
• •3. Patient developed oligometastasis, oligoprogression or oligopersistence after standard immunotherapy.
• •4. Be ≥18 years of age on day of signing informed consent.
• •5. Be willing to undergo repeat biopsy of tumor lesions according to the study protocol.
• •6. Patients who have failed the standard therapy, or who are unsuitable for standard treatment, or refuse chemotherapy.
• •7. At least one measurable lesion according to RECIST 1.1. A lesion that has previously received radiotherapy can be considered a target lesion only if this lesion is clearly progressed after radiotherapy.
• •8. The target lesions (irradiated lesions) are \> 5cm in in diameter
• •9. ECOG 0-2.
• •10. Life expectancy of \> 3 months.
• •11. Patients must have normal organ and bone marrow function as defined below: Total bilirubin \</= 1.5 x upper limit of normal (ULN). Aminotransferase (AST) Serum Glutamic Oxaloacetic Transaminase (SGOT)/ Alanine Aminotransferase (ALT) Serum Glutamic-Pyruvic Transaminase (SGPT) \<2.5 X institutional upper limit of normal (\</= 5 X institutional ULN for subjects with liver metastases) \*WBC \>/= 3500/uL, ANC \>/= 1500/uL \*Platelets \>/= 90K/ul \*Hemoglobin \>/= 9g/dL \*Creatinine \</= 1.5 x ULN, or creatinine clearance ≥ 50 ml/min（Cockcroft-Gault equation）. Coagulation: International Normalized Ratio (INR)≤ 1.5 × ULN, Partial thromboplastin time (PTT) ≤1.5 × ULN; left ventricular ejection fraction (LVEF) \>/= 50% and QTcF (Fridericia's formula) ≤ 450ms
• •12. Patients has recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to a previously administered agent.
• •13. Wash out period for chemotherapy is more than ≥ 4 weeks, for targeted small molecule therapy ≥ 5 half-lives; palliative radiotherapy must have been completed for at least ≥ 2 weeks, chest radiotherapy must have been completed for at least ≥ 4 weeks, and major surgery must have been completed for ≥ 4 weeks.
• •14. Subjects with no severe pulmonary ventilation dysfunction, no acute heart failure, and no contraindication to radiotherapy as judged by the radiotherapist. Subjects who agree to receive immunotherapy and radiotherapy treatment.
• •15. Subjects should agree to use an adequate method of contraception.