Radiation and Stress Fractures

I completed 15 radiation treatments on my spine last Thursday and now have a stress fracture. My doctor is scheduling me to see neuro neurolist now. How common is this to happen? I am an active person and had been doing my regular activities like playing in the garden during treatments. I felt great and then last week the pain in my back started. I wonder if I caused the fracture or this is a very common occurance? Am I suppose to be toning down my activities? I've just been going on with everything like always as I thought that to be a positive thing.

The pain meds work great until they fix this. But I want to get off the pain meds asap. Tomorrow I start my first chemo. Anyone know how they fix a stress fracture? I heard somewhere that they can give you a shot of something to fill the crack.