In Los Angeles, I would expect that IMRT would be the norm. I don't know how it would compare to older generation radiotherapy, but it was not a cake-walk.
I had 30 IMRT treatments to the left side of the face as well, from just above my collarbone up to the top of my cheekbone, and from midline on my nose to just of the midline on the back of my head.
The first thing that I lost was my sense of taste, and it just disappeared after the first week. It's back now, but still a bit "off" .
Fatigue, sore throat, mouth sores followed within a couple of weeks as well. Added bonuses were the burns on my neck and ear, in my nose, and of course losing the hair on half of the back of my head, and the entire left side of my moustahe gave me a "distinctive" look.
The 5th week was where things really went downhill for me, and stayed bad until about two weeks after the treatments ended. Since then, it's been steady improvement.
How poorly you feel is completely unique to each person. I'm a skinny 51 yr. old guy, and all things considered I did pretty well..I had one brief hospital stay towards the end of treatment, and never resorted to a feeding tube. Another fellow who started treatment the same week as I did, 15 years younger and 100 lbs bigger, a really sturdy lad, was terribly ill almost the whole time.
The norm is that you're going to be sick. Not likely incapacitated, unable to do anything at all sick, but sick. Plan on it, get your support network working for you, doing the stuff you aren't up to, and concentrate on getting through the treatments, staying hydrated and nourished.
Don't let either of those things slip. If you aren't taking in enough water and calories every day...EVERY DAY....you WILL be sicker than you've ever been before and you WILL wind up in hospital.
That sounds ominous, but it is something that almost everyone else here will tell you. It is a fact that one day of insufficient water or food (especially water) and you will be in trouble. It can be tough when you're throat is really sore, but it is incredibly important too.
Let us know what the Doctors say
Wayne