Hi Nellie, I will try to answer your questions in order:

1. The mask heeps your head and neck in precise alignment so that the radiation stays on target. With IMRT they want to be accurate to a millimeter. It is usually made of a thermoformed plastic mesh, molded to your face. It usually fits a little tight in the beginning but as you lose weight, becomes more comfortable. Also, since you will lose weight, there will be minimal pressure on the skin of the radiated area so you shouldn't suffer any pain. The mask is really not a big deal and you will get used to it quickly. It might help you to ask for some anti-anxiety meds, like Zanax as well, if you are really freaked out about this. I slept through many of my treatments.

2. I can't answer about the PEG I did it without one.

3. I kept all of my teeth. I wouldn't let them extract them. I would strongly recommend getting a second opinion about having any teeth pulled, especially since you are getting IMRT. If you keep your teeth first off they have to be in good shape going into this, secondly have repairs made now and dental trays made now. You will have to go the distance to maintain them under dry mouth conditions. Frequent flouride treatments, flossing, a Water Pik is helpful, get an extra soft babys tootbrush, Biotene tooth paste, mouth rinse an OraGel, etc. Check here for more info http://www.oralcancerfoundation.org/dental/dental-complications.htm