We heard back from Boston yesterday morning. I won't go in to great detail about what they said because it's mostly a repeat of things I've already explained. The overall verdict was that it's probably okay to try the Interferon and wait, with VERY close monitoring.
The proximity of the tumor mass to her optic chiasm (the part of the brain where the optic nerves cross) was enough to make them a bit nervous. Since the Interferon treatment won't treat the mass at all, the tumor mass will continue to grow. We have to be careful not to let it get too close to the optic chiasm where it could cause damage, or force us to include part of the optic chiasm in the field of radiation. Any damage done to that area would likely be irreversible, and the bit her vision has already suffered is enough!
They suggested staggering six-week checkups by a neuro-ophthalmologist with the six-week MRI schedule so we'd be checking in every three weeks, and would hopefully catch any significant changes early on.
We have an MRI on Friday morning (Summer's birthday!), followed by an appointment with Dr. Geyer. We'll be able to talk with him then about Boston's response (they've updated him as well) and confirm that we still want to move forward with the Interferon treatment.
I'll post again after that appointment.