Theresa:
I agree with everyone who has posted. Something does not sound right. First, you just can't try on a mask. The point of the mask is to keep you head from moving while doing radiation. If they didn't fit him for one, then how did he wear one as it's formed to your head???

I also don't understand about the light. Radiation does not have a "light". Plus as someone else stated, radiation is a planned treatment. The doctor's pinpoint where the radiation should be directed and they also try to save healthy tissue.
So it can't really be a one shot deal.

So, I would keep on asking questions. Get more information so that you can figure out what-is-what.

Good Luck. Please don't hesitate to ask questions.

Sandyst