Pitfalls and Immune-Related Adverse Events

The role of imaging including FDG PET/CT in response assessment, identification, and monitoring of immune-related adverse events (irAEs) is becoming more important given recent accelerated approvals of immunotherapeutic agents for several tumor types that previously had an extremely poor prognosis and lack of therapeutic options. However, the occurrence of irAEs presents challenges for distinction from progressive malignancy. Prompt and accurate imaging diagnosis of irAEs is important given their clinical impact. Due to ever-increasing the number of immunomodulatory agents with different modes of action and their expanding clinical indications, it is vital that clinicians are aware of various and emerging patterns of response and nonmalignant findings that can be associated with their use. It is therefore critical to systematically document the imaging features of irAEs that can be identified during immunotherapy, either as part of routine therapeutic response assessment or to investigate symptoms.