Objective: Cystic brain metastases (BMs) are rare in small cell lung cancer (SCLC), and there are limited data on the treatment and prognosis of cystic BMs. Whole brain radiotherapy has been the mainstay for BMs since several years. Immune checkpoint inhibitors in extensive stage small cell lung cancer (ES-SCLC) have been shown to be suitable for patients who experienced better overall survival and progress-free survival and have been approved as the first-line treatment for ES-SCLC. In this report, we described two ES-SCLC patients developed cystic BMs after immunotherapy, after which the patients continued to treat the primary lesion with immune checkpoint inhibitors and the cystic BMs with radiotherapy.
Case Description: Two male patients were diagnosed with ES-SCLC at the first admission and were subsequently treated with immunotherapy plus platinum therapy, during which cystic BMs developed. One patient received whole brain radiotherapy and the other received whole brain radiotherapy and Gamma knife radiosurgery (GKRS). Immunotherapy was continued after the brain lesions were controlled. It has been 33 months since the first patient was diagnosed and is now in stable condition. The other patient achieved an overall survival of 30 months.
Conclusion: This report describes two patients with cystic brain metastases in ES-SCLC. Whole brain radiotherapy has a good effect on local control of cystic brain metastases in small cell lung cancer and can significantly improve the symptoms of patients. At the same time, we treat immunotherapy as the first-line treatment, and then perform cross-immunotherapy after disease progression, combined with anti-vascular targeting drugs. The patient did not develop severe iRAEs.

Keywords: ES-SCLC, immunotherapy, cystic BMs, cross-line immunotherapy


中文翻译：

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广泛期小细胞肺癌伴囊性脑转移2例报告

目的：小细胞肺癌（SCLC）中囊性脑转移（BM）很少见，关于囊性脑转移的治疗和预后数据有限。多年来，全脑放疗一直是脑转移治疗的支柱。广泛期小细胞肺癌（ES-SCLC）的免疫检查点抑制剂已被证明适用于获得更好的总生存期和无进展生存期的患者，并已被批准作为 ES-SCLC 的一线治疗。在本报告中，我们描述了两名 ES-SCLC 患者在免疫治疗后出现囊性脑转移，之后患者继续使用免疫检查点抑制剂治疗原发灶，并使用放射治疗治疗囊性脑转移。
病例描述：两名男性患者在首次入院时被诊断为 ES-SCLC，随后接受免疫治疗加铂类治疗，期间出现囊性 BM。一名患者接受全脑放射治疗，另一名患者接受全脑放射治疗和伽玛刀放射外科（GKRS）。脑部病变得到控制后继续进行免疫治疗。自首例患者确诊以来已过去33个月，目前情况稳定。另一名患者的总生存期为 30 个月。
结论：本报告描述了两名 ES-SCLC 囊性脑转移患者。全脑放疗对小细胞肺癌囊性脑转移瘤的局部控制效果良好，可明显改善患者症状。同时，我们将免疫治疗作为一线治疗，病情进展后再进行交叉免疫治疗，联合抗血管靶向药物。患者没有出现严重的 iRAE。

关键词： ES-SCLC，免疫治疗，囊性脑转移，跨线免疫治疗