[Imaging of neurological adverse events associated with immunotherapies : Immune checkpoint inhibitors and CAR-T cells].

BACKGROUND

Immune checkpoint inhibitors (ICI) and chimeric antigen receptor T‑cell (CAR-T) therapies have fundamentally transformed oncology. With their increasing use, immune-related adverse events (irAEs) have gained attention, including those affecting the nervous system.

OBJECTIVES

To describe the clinical and imaging characteristics of neurological immune-related adverse events (NirAEs) under ICI and CAR‑T therapy, as well as their differential diagnostic and therapeutic implications.

MATERIALS AND

METHODS

Review of current literature on the incidence, clinical spectrum, and imaging features of NirAEs.

RESULTS

NirAEs occur in approximately 1-6% of patients treated with ICIs. Common manifestations include myositis, myasthenic syndromes, peripheral neuropathies, and various forms of encephalitis, which may differ clinically and radiologically from their idiopathic or paraneoplastic counterparts. Under CAR‑T therapy, immune effector cell-associated neurotoxicity syndrome (ICANS) represents the most frequent neurotoxic complication and affects about 30% of patients. Magnetic resonance imaging (MRI) is the imaging modality of choice but often reveals nonspecific or initially unremarkable findings. A pretherapeutic baseline MRI and close imaging follow-up improve diagnostic interpretation and prognostic assessment. Findings must always be interpreted within the clinical context and through interdisciplinary collaboration.

CONCLUSION

NirAEs are rare but potentially life-threatening. Due to unspecific imaging findings and overlapping differential diagnoses, close interdisciplinary cooperation between radiology, neurology, and oncology is essential. Early recognition and imaging follow-up are key to improving prognosis and survival.