Endovascular glue embolization of a radiation-induced lenticulostriate artery pseudoaneurysm in a pediatric patient with optic pathway glioma: Case report and review of literature.

Radiation-associated vascular changes most commonly present in the form of stenosis, thrombosis and occlusion. However, development of intracranial aneurysms secondary to radiation is far less common and often manifests with rupture. These aneurysms are difficult to treat and associated with high morbidity and mortality when ruptured compared with saccular aneurysms unrelated to radiation treatment. Both surgical and endovascular options are available for treatment of these aneurysms. We present a young patient with a radiation-induced intracranial pseudoaneurysm arising from the lenticulostriate branch of the left middle cerebral artery (MCA); this developed 1 year 4 months after 59.4 Gy of focused radiation to the suprasellar pilomyxoid astrocytoma. The patient successfully underwent endovascular glue embolization of the aneurysm and occlusion of the lenticulostriate artery after unsuccessful trapping of the aneurysm and occlusion of the parent artery using coils. She developed transient hemiparesis of the right side following the procedure, which was managed conservatively. We performed a complete review of the literature dealing with the radiation-induced intracranial aneurysms, their presentation, treatment and outcome.

Pediatric thalamic tumors in the MRI era: a Canadian perspective.

BACKGROUND: Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system. METHODS: We performed a Canadian multicenter retrospective review of pediatric thalamic tumors presenting during the MRI era (1989-2012). Radiology and pathology were reviewed by central independent reviewers. Paraffin shavings for RNA extraction were taken and tested for fusion events involving KIAA1549:BRAF. Tumors were classified as unilateral or bithalamic based on their origin on imaging. Univariate and multivariate analyses on factors influencing survival were performed. RESULTS: Seventy-two thalamic tumors were identified from 11 institutions. Females represented 53% of the study population, and the mean age at presentation was 8.9 years. Sixty-two tumors were unilateral and 10 bithalamic. Unilateral tumors had a greater propensity to grow inferiorly towards the brainstem. These tumors were predominantly low grade in comparison to bithalamic tumors which were high-grade astrocytomas. The 5-year overall survival was 61 ± 13% for unithalamic tumors compared to 37 ± 32% for bithalamic tumors (p = 0.097). Multivariate analysis indicated tumor grade as the only significant prognostic factor for unithalamic tumors. Six unilateral tumors, all low grade, were BRAF fusion positive. CONCLUSION: Unilateral and bilateral thalamic tumors behave differently. Surgical resection is an appropriate treatment option in unilateral tumors, most of which are low grade, but outcome is not related to extent of resection (EOR). Bilateral thalamic tumors have a poorer prognosis, but the occasional patient does remarkably well. The efficacy of chemotherapy and radiotherapy has not been clearly demonstrated. Novel therapeutic approaches are required to improve the prognosis for malignant unilateral thalamic tumors and bilateral thalamic tumors.