Radiation Enhances Anti-Tumor Activity of Checkpoint Blockade in Syngeneic Tumor Models

AACR 2018 -- More than 50% of cancer patients receive some sort of radiation therapy during the course of their illness. While radiation treatment is a mainstay in clinical oncology, there is limited preclinical data in syngeneic models. The advent of image-guided small animal irradiators such as the Small Animal Radiation Research Platform (SARRP; Xstrahl) allow for use of targeted focal irradiation (RT) in a broad range of models. Here we evaluated the use of RT to broaden efficacy and response duration of immunomodulatory therapies. In the GL261-Luc glioblastoma model we also examined possible changes in lymphoid and myeloid immune cells by flow cytometry and looked at infiltration of CD4+ T cells by immunohistochemistry.