Immune Checkpoint Inhibitor-Related Adverse Effects and ¹⁸F-FDG PET/CT Findings

Area of Science:

• Oncology
• Immunology
• Radiology

Background:

• Immune checkpoint inhibitors (ICIs) harness T cells to target tumors.
• T-cell activation can lead to autoimmune reactions, causing immune-related adverse effects (IRAEs).
• IRAEs manifest as inflammation, increasing 18F-FDG uptake in various tissues.

Purpose of the Study:

• To review the relationship between ICI treatments and IRAEs.
• To highlight the role of 18F-FDG PET/CT in identifying and assessing IRAEs.
• To discuss the clinical implications of IRAEs on 18F-FDG PET/CT.

Main Methods:

• Review of current literature on ICI therapy and IRAEs.
• Discussion of 18F-FDG PET/CT imaging principles.
• Analysis of characteristic 18F-FDG uptake patterns associated with IRAEs.

Main Results:

• ICI-induced IRAEs cause inflammatory changes detectable by 18F-FDG PET/CT.
• 18F-FDG uptake in IRAEs can mimic tumor recurrence or metastasis.
• Accurate interpretation of 18F-FDG PET/CT is vital to differentiate IRAEs from disease progression.

Conclusions:

• 18F-FDG PET/CT is essential for diagnosing, grading, and monitoring IRAEs.
• Identifying IRAEs can guide treatment modifications, including ICI interruption or anti-inflammatory therapy.
• Understanding IRAEs on PET/CT has prognostic value and aids in treatment response prediction.