I'm about to have my last radiation treatment. Fatigue was not at all an issue when I was on TC chemo. I never had much fatigue with radiation either - just maybe the last week - and it was something I could "work through". I'm naturally a night owl and not a napper - however I have recently enjoyed the pleasures of naps. On occasion I have "closed my eyes for 20 min" only to awake 2-3 hrs. later. :) I've been exercising throughout my treatment, not up to my pre-treatment level, but I did not want to forget how to use the elliptical. Plus my time on the elliptical is the only time I keep up with my podcasts.
Each of us is different as far as side effects - but if you don't pay too much attention to what everyone else suffers, you may just forget that there are side effects. You don't necessarily experience what someone else does - or in the same way.
Good luck with your RT. The practice I went to was very good, very individual oriented, gave good advice and did everything possible to make the treatments comfortable. If you have had chemo, the RT is much easier. Ask if you can bring some favorite music cd's to play. Although you probably won't be on the table too long. And wear clothes that are easy on/easy off.
Advice (for everyone): *Make sure the technicians* have the correct program plugged in for YOU, and not someone else.*