Just for clarification on repeat radiosurgery, I found the following passage in the "Radiosurgery Practice Guideline for Vestibular Schwannoma," issued by the International Radiosurgery Association in 2006. Among others, Drs. Lundsford, Kondziolka, and Noren were on the committee that issued the report. The full text is at
http://www.irsa.org/AN%20Guideline.pdf.
Repeat Radiosurgery
Since the tumor control rate after radiosurgery is 95–98%,
other management options after radiosurgery are rarely
needed. Repeat radiosurgery or microsurgery can be
considered for patients with documented tumor growth
after radiosurgery. Repeat Gamma Knife® radiosurgery
can be delivered safely without an increased risk of
complications as compared to the initial treatment.
This particular passage is attributed to Dr. Noren and specifically references GK (his specialty), but I can't see why it wouldn't extend to CK as well.
I'm not trying to advocate one form of (re)treatment over another, but I think it's important that if someone is facing this difficult situation that they be aware that they still have options and retreatment with radiosurgery can't be ruled out a priori.
Hope this helps,
JB