The Impact of Radiation Therapy on Lymphocyte Count and Survival in Metastatic Cancer Patients Receiving PD-1 Immune Checkpoint Inhibitors

Therapeutic radiation has conflicting immune effects: radiation therapy (RT)-induced immunogenic cell death can contribute to immune response, but lymphocytes are also sensitive to RT. It is unknown whether palliative RT leads to lymphopenia in patients treated with immune checkpoint inhibitors (ICIs) and whether this affects outcomes. As such, we sought to assess the impact of palliative RT on circulating lymphocyte count and...