Immunotherapy related pericardial effusion on chest CT.

Background: Immunotherapy has become a critical class of anticancer therapy in recent years, functioning by releasing brakes on the immune system that ultimately results in immune cell activation which eliminates cancer cells. Immune related adverse events (IRAEs) are a specific type of adverse event described in patients taking checkpoint inhibitor immunotherapy which results from unrestrained immune activation. Immune related pericardial effusion has been described however has not been comprehensively characterized. Here, we present the most extensive report to date detailing this adverse event.

Methods: We queried our medical record system to retrospectively identify patients on checkpoint inhibitor therapy for lung cancer who subsequently developed pericardial effusion. We analyzed the clinical and radiographic characteristics, prior therapies, treatment for the effusion, and outcomes in patients with immune related pericardial effusion and compared them to similar patients with pericardial effusion not attributable to checkpoint inhibitor therapy.

Results: Our data demonstrate that most of these pericardial effusions were small and not clinically significant. The majority were successfully treated with steroids or resolved spontaneously. Anti-PD-1 inhibitors were the most common checkpoint inhibitor preceding pericardial effusion, and a significant number of patients who went on to develop IRAE pericardial effusion previously had treatment with carboplatin for their cancer.

Conclusions: These data suggest that IRAE pericardial effusion is not a clinically significant adverse event however it sometimes leads to permanent discontinuation of checkpoint inhibitor therapy which is not necessary.