My sister and I both had DCIS, hers was intermediate grade. She didn't have radiotherapy or tamoxifen. I had high grade DCIS and have had radiotherapy and tamoxifen. So I guess it depends on what the pathology report says about the grade.
It's so hard waiting for results and wondering what will happen. If it's any help, I didn't find radiotherapy was any real problem, the worst thing is the travelling if you live a long way away. The thought was much worse than the treatment itself.
Hope you get good results from the pathology, sending you a hug.