Need help understanding treatments

Hi I'm trying to understand my mother in law's treatments for lung cancer. She was diagnosed a little over a year ago and her doctor was giving her large doses of chemo then he lowered that because the large doses where draining her very badly yesterday she called us and said she will be starting radiation therapy on thursday all the sites I've been to say that radiation is the starting treatment so is this normal? The tumor was increasing in size under the chemo but I'm not sure exactly what stage she's at or the type of radiation she's going to start but I'm really worried that she isn't getting proper care and I can't go with her to talk to her doctors because I have to stay with my children. I really need help understading all this I tried to find an idots guide to cancer but apparently the don't make one (sorry morbid joke) any advice would be appreciated.