In patients with oligometastatic (1-5 lesions) extensive-stage small cell lung cancer, to explore the efficacy and safety of Durvalumab immunotherapy combined with chemotherapy followed by consolidation radiotherapy, to provide scientific basis for the formulation of the best comprehensive treatment plan in the future.
Histology or cytology confirmed small cell lung cancer
The number of metastatic lesions is less than 5 (oligometastatic)
According to the seventh edition of the American Joint Cancer Board, IV or T3-4 cannot be included in the same tolerable radiation program due to the widespread distribution of multiple lung nodules or the large size of tumors / lymph nodes.
Four to six cycles of Durvalumab combined with standard chemotherapy (platinum + etoposide) were evaluated as CR（complete response） or PR（partial response） before entering the group.
Within 4 weeks before enrollment or within 5 half-lives of the drug (whichever is the longer), systemic immune stimulants (including but not limited to interferon, interleukin-2, tumor necrosis factor) are used (cancer vaccines are allowed in previous treatments)
Within 14 days before the first administration of the drug, any Chinese herbal medicine used to control cancer was used.
Any disease that must be treated with corticosteroids (prednisone > 10mg/ days or equivalent) or other immunosuppressive drugs within 14 days before enrollment Note: patients who have used or have used any of the following steroid regimens can be selected: epinephrine replacement steroids (prednisone ≤ 10mg/ days or equivalent). Inhaled corticosteroids with very low local, ocular, articular, nasal or systemic absorption; prophylactic use of prescription corticosteroids in a short course (≤ 7 days) or for the treatment of non-autoimmune diseases (such as delayed anaphylaxis caused by contact allergens)
Live vaccine is given within 4 weeks before joining the group. Note: seasonal influenza vaccine is usually an inactivated vaccine, and patients who receive such vaccine are allowed to join the group. The intranasal influenza vaccine is a live vaccine, and patients vaccinated with such vaccine are not allowed to enter the group.