Multiple Sclerosis-like Lesions Induced by Radiation: A Case Report and Systematic Review of the Literature.

Radiotherapy (RT) remains crucial in treating both primary and metastatic central nervous system cancer. Despite advancements in modern techniques that mitigate some toxic adverse effects, magnetic resonance imaging (MRI) scans still reveal a wide range of radiation-induced changes. Radiation can adversely affect neuroglial cells and their precursors, potentially triggering a demyelinating pattern similar to multiple sclerosis (MS). The aim of the current review is to investigate the occurrence and characteristics of such cases presented in the literature. We present the case of a 37-year-old female patient with multiple white matter lesions on a brain MRI, mimicking MS, after the completion of RT sessions. Additionally, a systematic review of the literature (PROSPERO id: CRD42024624053) was performed on 4 January 2024. The databases of MEDLINE and SCOPUS were searched. Case reports or case series of adult patients with white matter lesions in a brain MRI, consistent with the MAGNIMS criteria for MS plaques, after RT, were included in our final synthesis. The PRISMA guidelines were applied. The systematic search of the literature revealed 1723 studies, 7 of which conformed to our inclusion criteria, including seven patients in our final analysis. Four of them were female and the mean age was 39 ± 11 years. Several intracranial and extracranial RT types were performed. The symptoms occurred 3 ± 0.8 months after the completion of RT. Lesions were revealed in infratentorial, periventricular and subcortical white matter regions, but not in the spinal cord. All patients who received corticosteroids (83%) showed clinical improvement. Clinical and radiological recurrence occurred in two of the patients during the follow-up period. Fingolimod and Interferon beta-1a were administered to these two patients. Radiation-induced demyelination is a critical clinical and radiological entity that requires attention from both oncologists and neurologists. Comprehensive follow-up is essential to identify patients who may benefit from disease-modifying therapies and to distinguish them from those with pre-existing demyelinating conditions.