I had radiation after my lumpectomy. My nodes were also clean. First, you will meet with your radiologist, and he or she will make a small mark at the site to be radiated. Then you will go 5 days a week for the treatment. Your doctor will determine how many treatments you will get. I had 30, so I went for 6 weeks. It doesn't hurt at all and it only takes minutes. The worst part for me was going through rush hour traffic every morning for a 6 minute treatment. I didn't get tired or have any side effects other than a slight burn at the end. It was no worse than a very minor sunburn. Each week I met with the radiologist right after treatment. It really was a breeze, and I am a first class baby.
My only restriction was no topless sunbathing. Oh, my doc had a sense of humor I hope you are encouraged by the responses on this site.
Good luck. Let us know what you decide to do.