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.

Reversible hypothalamic dysfunction in optic nerve germinoma.

Primary optic apparatus germ cell tumors are rare. There have been only 6 cases reported in the literature. Although they often disturb the hypothalamus-pituitary-adrenal axis and cause progressive visual loss, the influence of treatment outcomes on hypothalamic autoregulation has never been mentioned. Here, we report a patient with an optic nerve germinoma who presented with reversible visual and hypothalamic dysfunction, and we discuss the possible mechanisms and pathogenesis.

Low grade chiasmatic-hypothalamic glioma-carboplatin and vincristin chemotherapy effectively defers radiotherapy within a comprehensive treatment strategy -- report from the multicenter treatment study for children and adolescents with a low grade glioma -- HIT-LGG 1996 -- of the Society of Pediatric Oncology and Hematology (GPOH).

BACKGROUND: Low grade gliomas arise in all CNS-locations and age groups, chiasmatic-hypothalamic tumors occur especially in young children. Early radiotherapy (RT) shall be deferred by chemotherapy (CT) within the concept of the HIT-LGG 1996 study, offering a comprehensive treatment strategy for all age groups. PATIENTS: 198 of 905 protocol patients (21.9 %) had a chiasmatic (34), chiasmatic-hypothalamic (144) or hypothalamic (20) primary tumor, median age at diagnosis 3.6 years (0.2-16.3 y.), 54 had neurofibromatosis (27.3 %), 108 female (54.5 %). 98 children had severe visual impairment as their first symptom. The initial neurosurgical intervention resulted in 5 complete, 26 subtotal, 45 partial resections, 67 biopsies; 55 children had a diagnosis on the basis of neuroradiologic findings. Histology showed 132 pilocytic astrocytoma I degrees , 6 astrocytoma II degrees /nos and 2 DIGG/DIA I degrees (3 not known). RESULTS: 82 children were treated at diagnosis, 68 upon clinical or radiological progression following observation times of 3.0 to 115.0 months. RT: 27 children received conventional (18) or interstitial (8) RT (1 not documented) at a median age of 7.3 years; 7 tumors went into further progression. At a median observation time of 50.1 months 21 tumors are stable, 3 regressive (2 not evaluable, 1 death). CT: 123 children received vincristin/carboplatin at a median age of 3.7 years. 105/123 achieved CR/PR/SD. 44/123 tumors were progressive after median 22.5 months, 37 with a chiasmatic-hypothalamic primary, 16/44 were irradiated. At a median observation time of 44.7 months 2 children are in complete remission, 92 tumors are stable, 8 regressive, 9 progressive. 4 children died, 8 are not evaluable. At 60 months overall survival of the cohort is 0.93; PFS of the CT-group is 0.61, the RT-free survival 0.83. Within the CT-group children with an age at diagnosis < 1 year and non-pilocytic histology are at increased risk for early progression. Causative factors cannot be defined, yet. CONCLUSION: Within the comprehensive treatment strategy for low grade glioma HIT-LGG 1996 chemotherapy is effective to delay the need for early radiotherapy in chiasmatic-hypothalamic glioma. More effective reduction of the risk for progression has to be sought for young children < 1 year.

Current and future strategies in radiotherapy of childhood low-grade glioma of the brain. Part I: Treatment modalities of radiation therapy.

BACKGROUND: Treatment of childhood low-grade gliomas is a challenging issue owing to their low incidence and the lack of consensus about "optimal" treatment approach. MATERIAL AND METHODS: Reports in the literature spanning 60 years of radiation therapy, including orthovoltage, megavoltage and recently modern high-precision treatments, were reviewed with respect to visual function, survival, prognostic factors, dose prescriptions, target volumes, and treatment techniques. Based on these experiences, future strategies in the management of childhood low-grade glioma are presented. RESULTS: Evaluation of published reports is difficult because of inconsistencies in data presentation, relatively short follow-up in some series and failure to present findings and results in a comparable way. Even with the shortcomings of the reports available in the literature, primarily concerning indications, age at treatment, dose response, timing and use of "optimal" treatment fields, radiation therapy continues to play an important role in the management of these tumors achieving long-term survival rates up to 80% or more. Particularly in gliomas of the visual pathway, high local tumor control and improved or stable visual function is achieved in approximately 90% of cases. Data on dose-response relationships recommend dose prescriptions between 45 and 54 Gy with standard fractionation. There is consensus now to employ radiation therapy in older children in case of progressive disease only, regardless of tumor location and histologic subtype. In younger children, the role of radiotherapy is unclear. Recent advances in treatment techniques, such as 3-D treatment planning and various "high-precision" treatments achieved promising initial outcome, however with limited patient numbers and short follow-ups. CONCLUSIONS: Radiation therapy is an effective treatment modality in children with low-grade glioma regarding tumor control and improvement and/or preservation of neurologic function or vision, respectively. More prospective studies are needed to address the impact of modern radiation therapy technologies (including intensity-modulated radiotherapy) on outcome especially in the very young and to define the role of radiation therapy as a part of a comprehensive treatment approach. The forthcoming prospective trial SIOP/GPOH LGG RT 2003 is addressing this issue.