Tell the oncologist you need to talk to her again. Get hold of the nurse at the radio unit and get her to come with you.
This stuff is really tricky from a political correctness point of view, but if you can't understand her it is perfectly reasonable to make a respectful request for clarification.
I think you will find she has given you the standard spiel about every treatment having potential side effects but you need to give informed consent, so you have to understand what the risks are. Ask for some literature--she should have something she can give you.
Rads seem like a doddle after chemo, but there are so many variables that you really can't compare your treatment with someone else's. The toxicity thing will relate to your particular dose, where it is delivered and what chance there is of periferal damage. Most cancer treatment involves some degree of toxicity, but it represents our best chance of survival.