Radiotherapy (RT) is a cornerstone of cancer treatment. Compared with conventional high-dose radiation, low-dose radiation (LDR) causes less damage to normal tissues while potentially modulating immune responses and inhibiting tumor growth. LDR stimulates both innate and adaptive immunity, enhancing the activity of natural killer cells, dendritic cells, and T cells. However, the mechanisms underlying the effects of LDR on the immune system remain unclear. To explore the history, research hotspots, and emerging trends in immune response to LDR literature over the past two decades. Publications on immune responses to LDR were retrieved from the Web of Science Core Collection. Bibliometric tools, including CiteSpace and HistCite, were used to identify historical features, active topics, and emerging trends in this field. Analysis of 1244 publications over the past two decades revealed a significant surge in research on immune responses to LDR, particularly in the last decade. Key journals such as , , and published pivotal studies. Citation networks identified key studies by authors like Twyman-Saint Victor C (2015) and Vanpouille-Box C (2017). Keyword analysis revealed hotspots such as ipilimumab, stereotactic body RT, and targeted therapy, possibly identifying future research directions. Temporal variations in keyword clusters and alluvial flow maps illustrate the evolution of research themes over time. This bibliometric analysis provides valuable insights into the evolution of studies on responses to LDR, highlights research trends, and identifies emerging areas for further investigation.