Immunomodulation with Radiation

Traditionally, radiation therapy (XRT) was thought of as exclusively means to treat local disease. However, recognition of responses outside the field of radiation, known as the abscopal effect, has led to a paradigm shift in our understanding of the application of XRT. Radiation therapy is increasingly being recognized for its role in altering the immune system. Recent research has highlighted how XRT influences antitumor immunity throughout each phase of the immune cycle, and there is rapidly growing preclinical evidence of the synergy between XRT and immunotherapy. Specifically, combinatorial strategies have demonstrated the ability to increase tumor antigen presentation, T cell priming and activation, T-cell-mediated killing, and more. Clinical trials using XRT with immunotherapy agents targeting these and other pathways are currently underway and initial results are promising. Herein we summarize the current preclinical landscape along with the results of past and ongoing clinical trials investigating the effects of XRT in combination with immunotherapy.