I wish you much luck with your desire to keep working, however I think the majority of those who have undergone radiation find that around the 3rd or 4th week, getting out of bed is a significant challenge.

After my surgery, which was very extensive with several complications following, I was told by my radiologist that the rads would likely be worse than the surgery. I scoffed at that idea; little did I know how accurate his prediction was.

There was a period of nearly 6 weeks where I was out of bed long enough to use the washroom, get in the car and be driven to the hospital, or have a shower. That was it. I could not have driven myself to work, much less even gotten into the office from the parking lot. it was fully 6 months before I was able to return to work on a part time basis.

There certainly are those rare individuals that don't have a tough time with rads, but I think you're better to prepare for them to knock you down than to ignore the likelyhood and have the side effects catch you off guard.

my 2 cents. your mileage may vary
Wayne