Dear Chris:
Sorry to hear about your son. The usual optic glioma in NF-1 is a pilocytic astrocytoma. There are several issues. The first is whether another round of the same chemotherapy might not be work on the tumor. The next question would be if phenyacetate might be warranted at this point before radiation. Radiation would be coned down to isolate the area of the optic glioma and would not be whole brain radiation. Pilocytic astrocytomas are sensitive to radiation. I would make a full check concerning alternatives to radiation, at this point. Go on the NF-1 internet site and see what others have done in your situation. I think I might favor phenyacetate before radiation. Ask your oncologist and pediatric neurologist to ask around and see what others have done.
Sincerely,
CCF Neuro MD