目前，化疗免疫疗法是广泛分期小细胞肺癌(ES-SCLC)的一线治疗方法。然而，只有0.8%至2.5%的患者在化疗免疫疗法后完全缓解。考虑到ES-SCLC对放疗非常敏感，第一线治疗后增加放疗可能进一步改善局部控制，可能对患者的生存有益。先前的研究表明，在对化疗反应良好的ES-SCLC患者中，巩固性胸部放疗(cTRT)可以减少疾病进展并改善总体生存率。然而，在免疫疗法时代，cTRT的疗效和安全性仍不清楚，因缺乏前瞻性研究。预防性颅内放疗(PCI)在先前的报告中已显示能降低有限分期SCLC患者的脑转移(BM)发生率并延长生存时间。然而，根据目前的指南，PCI并不常被推荐给ES-SCLC患者。免疫疗法有降低BM发生率的潜力。在免疫疗法时代，PCI能否被常规磁共振成像监测替代ES-SCLC仍存在争议。对于SCLC患者的脑转移，全脑放疗(WBRT)是标准治疗方法。立体定向放射治疗(SRS)在有限脑转移的治疗中显示出了希望。考虑到免疫疗法降低BM的潜力，SRS能否在免疫疗法时代替代WBRT治疗有限脑转移仍存在争议。此外，在加入免疫疗法后，姑息放疗在无症状转移病灶的患者中可能作用减弱。然而，在有明显转移病灶症状的患者中，例如脊髓压迫、上腔静脉综合征、肺叶梗阻和负重转移，姑息放疗仍然是不可或缺和紧迫的，这些症状可能严重影响生活质量和预后。为了改善ES-SCLC的结果，我们根据现有证据探讨了与免疫疗法相关的放疗的可行性，包括cTRT、PCI、WBRT/SRS和姑息放疗，这可能为进一步的随机试验和临床应用提供具体前景。版权所有©2023 Li、Zhao、Ma、Shao、Wang、Jin和Liu。

Currently, chemoimmunotherapy is the first-line treatment for extensive-stage small-cell lung cancer (ES-SCLC). However, only 0.8%-2.5% of the patients presented complete response after chemoimmunotherapy. Considering that ES-SCLC is highly sensitive to radiotherapy, the addition of radiotherapy after first-line treatment for ES-SCLC could further improve local control, which may be beneficial for patients' survival. Prior studies have shown that consolidative thoracic radiotherapy (cTRT) can decrease disease progression and improve overall survival in patients with ES-SCLC who respond well to chemotherapy. However, the efficacy and safety of cTRT in the immunotherapy era remain unclear owing to a lack of prospective studies. Prophylactic cranial irradiation (PCI) has been shown to decrease brain metastasis (BM) and prolong survival in patients with limited-stage SCLC in previous reports. However, according to current guidelines, PCI is not commonly recommended for ES-SCLC. Immunotherapy has the potential to reduce the incidence of BM. Whether PCI can be replaced with regular magnetic resonance imaging surveillance for ES-SCLC in the era of immunotherapy remains controversial. Whole brain radiation therapy (WBRT) is the standard treatment for BM in SCLC patients. Stereotactic radiosurgery (SRS) has shown promise in the treatment of limited BM. Considering the potential of immunotherapy to decrease BM, it is controversial whether SRS can replace WBRT for limited BM in the immunotherapy era. Additionally, with the addition of immunotherapy, the role of palliative radiotherapy may be weakened in patients with asymptomatic metastatic lesions. However, it is still indispensable and urgent for patients with obvious symptoms of metastatic disease, such as spinal cord compression, superior vena cava syndrome, lobar obstruction, and weight-bearing metastases, which may critically damage the quality of life and prognosis. To improve the outcome of ES-SCLC, we discuss the feasibility of radiotherapy, including cTRT, PCI, WBRT/SRS, and palliative radiotherapy with immunotherapy based on existing evidence, which may offer specific prospects for further randomized trials and clinical applications.Copyright © 2023 Li, Zhao, Ma, Shao, Wang, Jin and Liu.