@m3rt welcome to connect, I am glad you are here. The study provided above does talk about some new studies, mostly still in specific cases.
You stated that you are both hormone positive. So I would guess this is not overly cautious. Onco dx is a great test but it isn’t the only thing that can determine the best course of action. I think your doctor would like to reduce your risk of recurrence as much as possible.
If I had to choose between radiation and chemo, I would take radiation all day long, I have some experience with both.
Do you have specific concerns about radiation? Did your doctor mention taking endocrine therapy to reduce hormones?