Related Experiment Video
Updated: Jul 16, 2026
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Moyamoya following cranial irradiation for primary brain tumors in children
N J Ullrich1, R Robertson, D D Kinnamon
1Department of Neurology, Children's Hospital Boston, Boston, MA 02446, USA. nicole.ullrich@childrens.harvard.edu
Insights
Children receiving cranial radiation for brain tumors face risks of moyamoya syndrome. Higher radiation doses and neurofibromatosis type 1 (NF1) significantly increase this risk.
Area of Science:
- Pediatric Oncology
- Neurology
- Radiation Oncology
Background:
- Moyamoya syndrome is a rare cerebrovascular disorder characterized by progressive stenosis of the intracranial arteries, particularly at the circle of Willis.
- Cranial irradiation is a common treatment for pediatric brain tumors, but it can lead to long-term complications, including vascular abnormalities.
Purpose of the Study:
- To identify risk factors associated with the development of moyamoya syndrome in children treated with cranial irradiation for primary brain tumors.
- To analyze the relationship between radiation dose, specific tumor locations, and the incidence of moyamoya syndrome.
Main Methods:
- A retrospective review of 456 children treated with cranial irradiation for primary brain tumors.
- Analysis of neuroimaging studies, dosimetry data, and clinical variables in 345 patients using survival analysis techniques.
- Cox proportional hazards regression was used to assess the impact of radiation dose and neurofibromatosis type 1 (NF1).
Main Results:
- Moyamoya syndrome developed in 3.5% (12 patients) of the study cohort.
- Patients with neurofibromatosis type 1 (NF1) and those receiving higher radiation doses (>5,000 cGy) experienced a more rapid onset of moyamoya.
- Each 100-cGy increase in radiation dose elevated the moyamoya risk by 7% (HR=1.07), and NF1 tripled the risk (HR=3.07).
Conclusions:
- Moyamoya syndrome is a significant complication following cranial irradiation in pediatric brain tumor patients.
- Increased radiation dose to the circle of Willis and the presence of neurofibromatosis type 1 (NF1) are key risk factors for developing moyamoya syndrome.
- Close monitoring is recommended for children with these risk factors, especially those with tumors near the circle of Willis, such as optic pathway glioma.
Objective:
To study the risk factors for the development of moyamoya syndrome after cranial irradiation for primary brain tumors in children.
Methods:
We reviewed neuroimaging studies and dosimetry data for 456 children who were treated with radiation for a primary brain tumor and who were prospectively evaluated with serial neuroimaging studies and neurologic evaluations. A total of 345 patients had both adequate neuroimaging and radiation dosimetry data for further analysis. We used survival analysis techniques to examine the relationship of clinically important variables as risk factors for the development of moyamoya over time.
Results:
Overall, 12 patients (3.5%) developed evidence of moyamoya. The onset of moyamoya was more rapid for patients with neurofibromatosis type 1 (NF1) (median of 38 vs 55 months) and for patients who received >5,000 cGy of radiation (median of 42 vs 67 months). In a multiple Cox proportional hazards regression analysis controlling for age at start of radiation, each 100-cGy increase in radiation dose increased the rate of moyamoya by 7% (hazard ratio [HR] = 1.07, 95% CI: 1.02 to 1.13, p = 0.01) and the presence of NF1 increased the rate of moyamoya threefold (HR = 3.07, 95% CI: 0.90 to 10.46, p = 0.07).
Conclusions:
Moyamoya syndrome is a potentially serious complication of cranial irradiation in children, particularly for those patients with tumors in close proximity to the circle of Willis, such as optic pathway glioma. Patients who received higher doses of radiation to the circle of Willis and with neurofibromatosis type 1 have increased risk of the development of moyamoya syndrome.
