Suggest Treatment For Cavernous Angioma

My Daughter has been recently diagnosed with a cavernous angioma. She had a Medullablastoma in 1984, at age 10. She underwent surgery and radiation. Since then she has had multiple surgeries to remove Meningiomas, explained to me as radiation induced. She has recovered nicely from the surgeries. Recently they found the cavernous angioma after an episode, a bleed . The Neurosurgeon said it had grown since Sept 2014, She is taking 1mg of decadron, to help with the symptoms. It is located near the brain stem in the cerebellar peduncle. How do these grow and once they start a bleed, can they stop growing and remain stable, also could this be radiation induced?...are cyberknife or gamma(?) effective ways to remove this , so she may return to a more normal life. Are there any medications that could stop the growth? Thank you, Nancy