External beam radiotherapy is used for radical treatment of organ-confined prostate cancer and to treat lesions in metastatic disease whereas molecular radiotherapy with labelled prostate-specific membrane antigen ligands and radium-223 (²²³Ra) is indicated for metastatic prostate cancer and has demonstrated substantial improvements in symptom control and overall survival compared with standard-of-care treatment. Prostate cancer is considered an immunologically cold tumour, so limited studies investigating the treatment-induced effects on the immune response have been completed. However, emerging data support the idea that radiotherapy induces an immune response in prostate cancer, but whether the response is an antitumour or pro-tumour response is dependent on the radiotherapy regime and is also cell-line dependent. In vitro data demonstrate that single-dose radiotherapy regimes induce a greater immune-suppressive profile than fractionated regimes; less is known about the immune response induced by molecular radiotherapy agents, but evidence suggests that these agents might induce an immune-suppressive systemic immune response, indicated by increased expression of inhibitory checkpoint molecules such as programmed cell death 1 ligand 1 and 2, and that these changes could be associated with clinical response. Different radiotherapy modalities can induce distinct immune profiles, which can either activate or suppress immune-mediated tumour killing and the current preclinical models used for prostate cancer research are not yet optimal for studying the complexity of the radiotherapy-induced immune response.

外照射放疗用于器官局限型前列腺癌的根治性治疗和转移性疾病的病变，而使用标记的前列腺特异性膜抗原配体和镭 223 （²²³Ra） 的分子放疗适用于转移性前列腺癌，并且已证明与标准护理治疗相比，症状控制和总生存期有显着改善。前列腺癌被认为是一种免疫寒冷的肿瘤，因此已经完成了调查治疗诱导对免疫反应影响的有限研究。然而，新出现的数据支持放疗在前列腺癌中诱导免疫反应的观点，但反应是抗肿瘤反应还是促肿瘤反应取决于放疗方案，也取决于细胞系。体外数据表明，单剂量放疗方案比分次放疗方案诱导的免疫抑制作用更强;对分子放疗药物诱导的免疫反应知之甚少，但有证据表明，这些药物可能会诱导免疫抑制性全身免疫反应，表现为抑制性检查点分子（如程序性细胞死亡 1 配体 1 和 2）的表达增加，并且这些变化可能与临床反应有关。不同的放疗方式可以诱导不同的免疫特征，从而激活或抑制免疫介导的肿瘤杀伤，目前用于前列腺癌研究的临床前模型还不是研究放疗诱导的免疫反应复杂性的最佳选择。