18F-FDG PET/CT-visualised immune-related hepatitis after immune checkpoint inhibitor combination treatment in a patient with metastatic melanoma.

The use of immune checkpoint inhibitors has evolved over the past decade, leading to increased survival in several cancers, including metastatic melanoma. However, the activation of the immune system can cause immune-related adverse events (irAEs), some of which may be potentially fatal. Several irAEs can be visualised on 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT), but only a few short cases of immune-related hepatitis have been described in the literature. This case describes thoroughly a course of immune-related hepatitis visualised on a scheduled 18F-FDG PET/CT performed to assess treatment response in a patient treated with combination immunotherapy (ipilimumab and nivolumab) for metastatic melanoma. Although rare, this irAE can be fatal and highlights the importance of assessing the liver when evaluating 18F-FDG PET/CT scans and alerting clinicians in case of suspicious increased FDG uptake in the liver to optimise patient treatment and care.