Radiotherapy (RT) is delivered for purposes of local control, but can also exert systemic effect on remote and non-irradiated tumor deposits, which is called abscopal effect. The view of RT as a simple local treatment has dramatically changed in recent years, and it is now widely accepted that RT can provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). Nevertheless, several points remain to be addressed such as the interaction of RT and immune system, the identification of the best schedules for combination with immunotherapy (IO), the expansion of abscopal effect and the mechanism to amplify iRT. To answer these crucial questions, we roundly summarize underlying rationale showing the whole immune landscape in RT and clinical trials to attempt to identify the best schedules of iRT. In consideration of the rarity of abscopal effect, we propose that the occurrence of abscopal effect induced by radiation can be promoted to 100% in view of molecular and genetic level. Furthermore, the “radscopal effect” which refers to using low-dose radiation to reprogram the tumor microenvironment may amplify the occurrence of abscopal effect and overcome the resistance of iRT. Taken together, RT could be regarded as a trigger of systemic antitumor immune response, and with the help of IO can be used as a radical and systemic treatment and be added into current standard regimen of patients with metastatic cancer.

放射治疗 (RT) 是为了局部控制的目的而进行的，但也可以对远程和未照射的肿瘤沉积物产生全身作用，这被称为远隔效应。近年来，放疗作为一种简单的局部治疗的观点发生了巨大变化，现在人们普遍认为放疗可以引发全身免疫反应，这为放疗和免疫治疗 (iRT) 的结合提供了强有力的理由。尽管如此，仍有几个问题需要解决，例如 RT 与免疫系统的相互作用、确定与免疫治疗 (IO) 联合的最佳方案、扩大远隔效应和放大 iRT 的机制。为了回答这些关键问题，我们全面总结了显示 RT 和临床试验中整个免疫景观的基本原理，以试图确定 iRT 的最佳时间表。考虑到异位效应的罕见性，我们提出从分子和基因水平上可以将辐射诱发的异位效应的发生率提高到100%。此外，“辐射效应”是指使用低剂量辐射对肿瘤微环境进行重新编程，可能会放大远视效应的发生并克服 iRT 的抵抗力。综上所述，RT可被视为全身抗肿瘤免疫反应的触发物，在IO的帮助下，可作为一种根治性和全身性治疗，并被添加到目前转移性癌症患者的标准治疗方案中。“radscopal 效应”是指使用低剂量辐射对肿瘤微环境进行重新编程，可能会放大异位效应的发生并克服 iRT 的抵抗力。综上所述，RT可被视为全身抗肿瘤免疫反应的触发物，在IO的帮助下，可作为一种根治性和全身性治疗，并被添加到目前转移性癌症患者的标准治疗方案中。“radscopal 效应”是指使用低剂量辐射对肿瘤微环境进行重新编程，可能会放大异位效应的发生并克服 iRT 的抵抗力。综上所述，RT可被视为全身抗肿瘤免疫反应的触发物，在IO的帮助下，可作为一种根治性和全身性治疗，并被添加到目前转移性癌症患者的标准治疗方案中。