Park CK, et al. - The authors planned this study to examine the outcomes of gamma knife radiosurgery (GKRS) for pediatric patients with brain arteriovenous malformation (AVM) and to explore the variables that influence obliteration. In most pediatric patients, GKRS produced good long-term clinical outcomes. Specific factors correlated with a low rate of obliteration in pediatric AVMs were multiple arterial feeding vessels, diffuse nidus structure, and fast flow of AVM.

• A total of 68 pediatric patients (≤ 18 years) were examined, with a mean follow-up period of 61.9 months (range 6–215 months).
• The authors analyzed the following parameters to determine their influence on obliteration of AVM treated by GKRS: age, sex, target volume, irradiation dose, prior treatment, location of AVM, nidus structure, velocity of AVM, location of venous drainage, number of feeding arteries, and initial presenting symptoms.
• They also estimated clinical factors which ought to be considered during the follow-up period.

• The authors confirmed complete obliteration in 26 patients (38.2%) by cerebral angiography among the 68 patients.
• For GKRS, the response rate of AVM was 92.6%.
• They observed no significant association between any of the parameters investigated and the obliteration of AVM, with the exception of number of feeding arteries, which exhibited a statistically significant difference by univariate analysis (p = 0.003).
• On multivariate analysis, however, nidus structure (p = 0.007), velocity of the main arterial phase (p = 0.013), velocity of the feeding artery phase (p = 0.004), and the number of feeding arteries (p = 0.018) revealed statistical significance.