Very technically, the term hemangioma is not correct here. Vascular malformation might be the correct term to use. Doctors tend to use the term for adults, but hemangiomas are a childhood-only birthmark. Rather than research hemangioma, look up the terms "vascular malformation," "arterio venous malformation," or "AVM."
So far, though, the treatment seems correct. Are they going to remove it?