Remote acute demyelination after focal proton radiation therapy for optic nerve meningioma

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

Background/Objectives: 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. Methods: 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. Results: 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. Conclusions: 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.

Primary and Secondary Optic Nerve Sheath Meningioma

Objective  This study was aimed to review issues relating to the recognition, radiographic diagnosis, monitoring, and management of primary and secondary optic nerve sheath meningioma (ONSM). Design  This study is a review of peer-reviewed literature combined with illustrative case studies. Participants and Methods  A literature search was conducted via the PubMed database using pertinent search terms. Selected articles were limited to those written or translated into English. Additional works cited within articles were also included. Individual cases were drawn from the experience of a tertiary academic neuroophthalmic and orbital practice. Tables summarize radiotherapeutic and surgical studies, excluding single case reports and studies focusing on meningioma of intracranial origin. Main Outcome Measurements  Review of reported surgical and radiotherapeutic series is the primary measurement. Results  The natural history of optic nerve sheath meningiomas is primarily characterized by progressive ipsilateral vision loss. Diagnosis is typically based on radiographic imaging findings, with biopsy remaining indicated in some patients. Management strategies may include observation, radiation, and/or surgical intervention, or a combination of these approaches. The role of surgery, especially with respect to primary ONSM (pONSM), remains controversial. Advancement of radiotherapy techniques has shifted modern treatment paradigms in pONSM toward radiation as primary treatment, as surgical outcomes are inferior in major studies. Although radiation remains the treatment of choice in many cases, selected patients may benefit from surgery, especially in the setting of secondary ONSM (sONSM). Conclusion  A wide variety of radiotherapeutic and surgical treatment modalities for ONSM exist. The specific indications for each management strategy continue to be redefined.

Spectrum of neuroimaging findings post-proton beam therapy in a large pediatric cohort

PURPOSE

Proton beam therapy (PBT) is now well established for the treatment of certain pediatric brain tumors. The intrinsic properties of PBT are known to reduce long-term negative effects of photon radiotherapy (PRT). To better understand the intracranial effects of PBT, we analyzed the longitudinal imaging changes in a cohort of children with brain tumors treated by PBT with clinical and radiotherapy dose correlations.

MATERIALS AND METHODS

Retrospective imaging review of 46 patients from our hospital with brain tumors treated by PBT. The imaging findings were correlated with clinical and dose parameters.

RESULTS

Imaging changes were assessed by reviewing serial magnetic resonance imaging (MRI) scans following PBT over a follow-up period ranging from 1 month to 7 years. Imaging changes were observed in 23 patients undergoing PBT and categorized as pseudoprogression (10 patients, 43%), white matter changes (6 patients, 23%), parenchymal atrophy (6 patients, 23%), and cerebral large vessel arteriopathy (5 patients, 25%). Three patients had more than one type of imaging change. Clinical symptoms attributable to PBT were observed in 13 (28%) patients.

CONCLUSION

In accordance with published literature, we found evidence of varied intracranial imaging changes in pediatric brain tumor patients treated with PBT. There was a higher incidence (10%) of large vessel cerebral arteriopathy in our cohort than previously described in the literature. Twenty-eight percent of patients had clinical sequelae as a result of these changes, particularly in the large vessel arteriopathy subgroup, arguing the need for angiographic and perfusion surveillance to pre-empt any morbidities and offer potential neuro-protection.