Transient intracranial imaging features on MRI following intra-arterial chemotherapy for intraocular and orbital malignancies

Intra-arterial chemotherapy (IAC) has become a mainstay treatment for retinoblastoma and has been used for lacrimal gland malignancies, enabling lower chemotherapeutic dosages while achieving higher local drug concentrations and reducing systemic side effects. We retrospectively report three patients who received IAC for retinoblastoma and lacrimal gland malignancies and subsequently developed peri-procedural clinical symptoms associated with transient intracranial magnetic resonance imaging (MRI) findings. In the first case, a patient with lacrimal gland carcinoma ex-pleomorphic adenoma was treated with two cycles of intra-arterial cisplatin and developed seizure-like symptoms, alongside MRI edema-like signals in the left frontal and temporal lobes. In the second case, a patient with bilateral retinoblastomas underwent combination IAC therapy and later experienced visual disturbances correlated with MRI abnormalities in the left occipital lobe. In the third case, a patient with right eye retinoblastoma received a similar IAC regimen and afterwards presented with neurologically non-correlative clinical symptoms. This prompted an intracranial MRI, which revealed a right frontal lobe gyral signal abnormality. Additionally, subsequent MRI exhibited new findings in the right optic chiasm and prechiasmatic optic nerve. In all cases, the imaging abnormalities and clinical symptoms eventually resolved, and follow-up imaging demonstrated no evidence of permanent structural brain parenchymal damage. Neurointerventional oncology is an evolving field, and our case series contributes to the increasing acknowledgment of its expanding indications. To the best of our knowledge, such transient intracranial imaging features following IAC have not been previously reported. Therefore, it is important for neurointerventionalists to recognize the transient nature of MRI findings highlighted by our reported cases.