Immunologic response of combined interleukin-2 and stereotactic body radiotherapy

Cytokine therapies have been available for the treatment of several cancers since the 1980s, with variable success. Since that time, the prevalence of metastatic disease has rapidly risen in the U.S. population as result of improvements in systemic and supportive therapies (1). In particular, there has been considerable advancement in targeted inhibitors of human ligands and receptors, which generally offer reduced toxicities compared to cytotoxic chemotherapy. Recently, this approach has been applied to the field of cancer immunotherapy, which aims to enhance the native immune system for the purpose of destroying malignant cells.