放射治疗是大多数癌症患者标准的治疗方法之一。由于辐射的影响，肿瘤细胞和周围环境都会直接受到影响，这主要影响但也可能限制免疫反应。多种免疫因素在癌症进展和放射治疗反应中发挥作用，包括免疫肿瘤微环境和系统免疫所称的免疫景观。异质性肿瘤微环境和不同的患者特征使放射治疗与这一免疫景观的动态关系变得复杂。在本综述中，我们将介绍目前关于放射治疗与免疫景观相关的免疫景观概述，以提供洞察并鼓励进一步改进癌症治疗的研究。对放射治疗对免疫景观的影响的调查显示，在几种癌症中，辐射后免疫反应具有共同的模式。放射治疗导致浸润性T淋巴细胞的增加和程序性死亡配体1（PD-L1）的表达，这可能暗示了与免疫疗法结合时对患者有益。尽管如此，冷瘤或由辐射引起的肿瘤微环境中的淋巴细胞减少被认为是患者生存的重要障碍。在几种癌症中，辐射后看到了免疫抑制人口的增加，主要是促肿瘤的M2巨噬细胞和髓源性抑制细胞（MDSCs）。最后，我们将强调放射参数本身如何影响免疫系统，并因此利用其对患者的好处。版权所有©2023 Iliadi、Verset、Bouchart、Martinive、Van Gestel和Krayem。

Radiotherapy is part of the standard of care treatment for a great majority of cancer patients. As a result of radiation, both tumor cells and the environment around them are affected directly by radiation, which mainly primes but also might limit the immune response. Multiple immune factors play a role in cancer progression and response to radiotherapy, including the immune tumor microenvironment and systemic immunity referred to as the immune landscape. A heterogeneous tumor microenvironment and the varying patient characteristics complicate the dynamic relationship between radiotherapy and this immune landscape. In this review, we will present the current overview of the immunological landscape in relation to radiotherapy in order to provide insight and encourage research to further improve cancer treatment. An investigation into the impact of radiation therapy on the immune landscape showed in several cancers a common pattern of immunological responses after radiation. Radiation leads to an upsurge in infiltrating T lymphocytes and the expression of programmed death ligand 1 (PD-L1) which can hint at a benefit for the patient when combined with immunotherapy. In spite of this, lymphopenia in the tumor microenvironment of 'cold' tumors or caused by radiation is considered to be an important obstacle to the patient's survival. In several cancers, a rise in the immunosuppressive populations is seen after radiation, mainly pro-tumoral M2 macrophages and myeloid-derived suppressor cells (MDSCs). As a final point, we will highlight how the radiation parameters themselves can influence the immune system and, therefore, be exploited to the advantage of the patient.Copyright © 2023 Iliadi, Verset, Bouchart, Martinive, Van Gestel and Krayem.