SBRT/LDRT in Combination With Camrelizumab and Apatinib in Metastatic Non-small Cell Lung Cancer Patient Previously Treated With PD-1/L1 Inhibitor and Chemotherapy

Inclusion Criteria: * Histological or cytological diagnosis of non-small cell lung cancer（NSCLC） * Has previous treatment with PD-1/L1 monoclonal antibody in combination with a platinum-based chemotherapy with outcome of complete remission (CR), partial remission (PR), or stable disease (SD) for ≥ 6 months * Has at least two disseminated lesions for LDRT and SBRT, respectively * Has a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Status * Has confirmation that epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) or ROS Proto-Oncogene 1(ROS1)-directed therapy is not indicated * Has adequate organ function * For female subjects of childbearing potential, a serum pregnancy test should be performed within 7 days prior to the administration of the first study intervention (study drug, radiation therapy) and have a negative result. Subjects are required to agree to use highly effective contraception (i.e., a method with a failure rate of less than 1% per year) and continue until at least 180 days after discontinuation of trial treatment Exclusion Criteria: * Imaging (CT or MRI) shows evidence of tumour invasion of large blood vessels or poorly demarcated blood vessels or the presence of cavities and necrotic lesions in the lungs * With active bleeding or perforation or a hereditary or acquired bleeding tendency present, with a daily haemoptysis of ≥2.5mL in the 3 months prior to screening. * with hypertensive disorders that cannot be reduced to the normal range with antihypertensive medication (systolic blood pressure ≤ 140 mmHg / diastolic blood pressure ≤ 90 mmHg). * Urine routine suggesting urine protein ≥ (++) and 24-hour urine protein amount ≥ 1.0g. * presence of thrombotic disease requiring long-term anticoagulation with warfarin or heparin, or requiring long-term antiplatelet therapy (aspirin ≥ 300 mg/day or clopidogrel ≥ 75 mg/day). * Previous systemic antitumour therapy other than PD-1(L1) monoclonal antibody in combination with platinum-based chemotherapy, or previous treatment with anti-angiogenic agents (including bevacizumab, apatinib, anlotinib, etc.). * Immune-related adverse events in previous PD-1(L1) therapy leading to treatment discontinuation * Symptomatic, untreated or actively progressing central nervous system (CNS) metastases are confirmed by CT or MRI assessment during screening and prior to radiographic evaluation. * Subjects with grade II or above myocardial ischemia or myocardial infarction and poorly controlled arrhythmias (QTc interval \> 450 ms for males and QTc interval \> 470 ms for females). Subjects with grade III-IV cardiac insufficiency or with left ventricular ejection fraction (LVEF) less than 50% according to NYHA criteria * Has known history of Human Immunodeficiency Virus (HIV) * Untreated active hepatitis B * Subjects have active hepatitis B