Sarah
I asked my doctors to show me a map of the radiation effected area and how the dose go through the body. The angles they use and how much of my lung or chest cavity was going to be exposed to what amount of radiation. My biggest fear was getting too much radiation in lungs etc. They were very helpful and showed me a map of X ray intensity and depth of chest cavity profile. Mind you I had my treatment in Japan where you do not get given much information at all. So the doctors in Australia should be more helpful. This information was very helpful to me to deciding to take 33 sessions of radiation vs 25. Since I am under 4o (going to be 38 soon) they gave much higher dose and very surface of my chest got some radiation.
Good luck to your mum with everything. My family tells me it was harder for them to see me go through the whole treatment from far. My parents live in Melbourne too while at the time I live in Japan. So I can appreciate how you must be feeling living on the otherside of Australia