E2857. Complications of Immune-Checkpoint Inhibitor Therapy
  1. William Erly; Moffitt Cancer Center
  2. James Costello; Moffitt Cancer Center
  3. Veronica Arteaga; Moffitt Cancer Center
  4. Joaquim Farinhas; Moffitt Cancer Center
  5. Sergiy Kushchayev; Moffitt Cancer Center
  6. Edwin Peguero; Moffitt Cancer Center
  7. Nafi Aygun; Moffitt Cancer Center
Immune-checkpoint inhibitors (ICIs) are recently developed monoclonal antibodies that can restore innate antitumor immunity and are effective in treating a variety of malignancies. In the healthy individual, immune suppressing surface receptors exist that, when activated, induce immune tolerance and prevent autoimmune disease. Neoplasms may co-opt this pathway to develop a relatively immune-free microenvironment that allows for tumor growth. ICIs prevent the activation of immunosuppressive pathways, reintroducing innate anti-tumor immunity. As the role for ICIs in cancer therapy increases, complications are more frequent.

Educational Goals / Teaching Points
The aim of this exhibit is to describe and illustrate some of the more common findings of ICI-related adverse immune reactions. At the conclusion the reader should be aware of some of the more common ICIs associated adverse immune reactions, and types of neoplasms that may be treated with ICIs.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Because ICIs result in activation of the immune system, the complications of therapy may involve virtually any organ system. These include but are not limited to the skin (up to 50%), gastrointestinal (40%), endocrine (34%), pulmonary (7%), and neurological (4.5%). Enteritis or colitis are the most common abnormalities of the gastrointestinal tract. On imaging, this most commonly manifest as non-specific bowel wall thickening, although more severe findings may occur. Pulmonary disease can be life threatening and may be difficult to diagnose, especially in patients with lung cancer who have pre-existing chronic lung disease. Cryptogenic organizing pneumonia occurs most frequently, although ARDS, sarcoid-like reactions, and acute interstitial pneumonitis may occur. Hypophysitis and thyroiditis are the most common endocrine syndromes. Neurologic manifestations frequently occur in conjunction with systemic disease and may include encephalitis, Guillain-Barre syndrome, demylelinating polyneuropathy, cerebellar ataxia, headache, and myopathies.

Because the complications of ICI therapy are so diverse, and the indications and usage increase, it is important for the radiologist to be cognizant of its imaging presentations to arrive at an accurate diagnosis.