What did Kelly hate about going to radiation treatments and why did the technicians have to be especially careful when administering the treatments?

Kelly began her radiation treatments. She hated the waiting room where everyone talked about their tumors, chances of recurrence and friends or family members who had died from undetected tumors. One time when Kelly was being prepared for her treatment, the technician noticed that her skin was burned. He reminded her to use aloe. Several pictures were taken during each visit. The techs had to be careful because Kelly's heart was so close to the target area. Later, Edward reminded her that she had just three weeks more of radiation and the whole cancer ordeal would be behind them.