Headaches after cyber knife radiation

[Pbellovin]

I had translab surgery 2 years ago for my AN. Unfortunately the 5 percent of the tumor that was left because it was too close to my facial nerve has started to grow.
Three weeks ago I had 3 cyber knife radiation treatments and now, three weeks later I am getting pretty bad headaches on the side that was treated. Has anyone had this side effect from radiation and how long did the headaches last or do they ever go away?