Radiotherapy (RT) is a highly effective anticancer treatment that is delivered to more than half of all patients with cancer. In addition to the well-documented direct cytotoxic effects, RT can have immunomodulatory effects on the tumour and surrounding tissues. These effects are thought to underlie the so-called abscopal responses, whereby RT generates systemic antitumour immunity outside the irradiated tumour. The full scope of these immune changes remains unclear but is likely to involve multiple components, such as immune cells, the extracellular matrix, endothelial and epithelial cells and a myriad of chemokines and cytokines, including transforming growth factor-β (TGFβ). In normal tissues exposed to RT during cancer therapy, acute immune changes may ultimately lead to chronic inflammation and RT-induced toxicity and organ dysfunction, which limits the quality of life of survivors of cancer. Here we discuss the emerging understanding of RT-induced immune effects with particular focus on the lungs and gut and the potential immune crosstalk that occurs between these tissues.

放射治疗 (RT) 是一种高效的抗癌治疗方法，一半以上的癌症患者都接受过放射治疗。除了有据可查的直接细胞毒性作用外，放疗还可以对肿瘤和周围组织产生免疫调节作用。这些效应被认为是所谓的远隔反应的基础，即放疗在受辐射的肿瘤外产生全身性抗肿瘤免疫力。这些免疫变化的全部范围尚不清楚，但可能涉及多种成分，例如免疫细胞、细胞外基质、内皮和上皮细胞以及无数趋化因子和细胞因子，包括转化生长因子-β (TGFβ)。在癌症治疗期间暴露于放疗的正常组织中，急性免疫变化可能最终导致慢性炎症以及放疗引起的毒性和器官功能障碍，从而限制癌症幸存者的生活质量。在这里，我们讨论了对放疗引起的免疫效应的新认识，特别关注肺和肠道以及这些组织之间发生的潜在免疫串扰。