Radiation Therapy And Immune-Related Side Effects In Patients Treated With Pd-1 Inhibitors.

207Background: Checkpoint inhibitors exert their antitumor effects by producing a heightened immune state, and inadvertently give rise to immune-mediated toxicities, including pneumonitis and hypothyroidism. We investigated whether these side effects were more common in patients who were treated with both PD-1 inhibitors and radiation. Methods: Our institution’s pharmacy database was used to collect data on patients who received ≥ 1 dose of PD-1 inhibitors, with or without radiation before August 31, 2016. Adverse effects of hypothyroidism, and pneumonitis were recorded and graded based on CTCAEv4. A logistic regression analysis was performed between radiation and hypothyroidism among patients with Hodgkin’s lymphoma (HL) and head and neck squamous cell carcinoma (HNSCC) and between radiation therapy (RT) and pneumonitis in lung cancer patients. Results: 231 patients received at least one dose of PD-1 inhibitors prior to data cut-off. Median age was 65 (24-92). There were 125 patients (54%) with lung canc...