Dear @ema1 - My DCIS was stage 0 as well. However, I had no clear upper margins. I, too, was VERY concerned about getting any type of radiation. BUT, sometimes, one has to accept the pits with the cherries!

A good resource:
https://www.mayoclinic.org/tests-procedures/radiation-therapy-for-breast-cancer/about/pac-20384940
As the article above will explain, there are two main types of Radiation Treatments: External Beam Radiation Therapy and Brachytherapy. I had the "External-Beam Radiation Therapy"; the most common form of radiation treatment for breast cancer. My radiation oncologist, very experienced, told me he would have me lay on my BELLY. This is how they prevent potential damage to the heart and lungs.

Brachytherapy is the other radiation therapy method. This is when radioactive pellets (also called seeds) are placed inside your breast near the tumor site. However, many things limit the use of Brachytherapy; I was NOT a candidate for that.

You may want to ask your Radiation Oncologist to explain the differences between the two methods and which one you would be a candidate for. Also, ask about which of the two is most successful.

I know, it isn't easy to travel this road! In spite of the newest ways hospitals try to support patients - for instance employing "Nurse Navigators", it seems that a lot of it is still a do-it-yourself adventure. And not the best of adventures, either!

The shock, fear, and anxiety one feels after being told she (or he) has cancer is off the chart. I am a very confident, assertive person, but I felt totally lost. I felt I needed someone to tell me what to do, who to call, who to see, how to find the right information .... I needed HELP! But no one was seemingly there for me. There were pieces of information, but not enough to reassure me. That's when I decided that if I would ever get to the end of that first part of the journey, I would never forget all my sisters (and brothers) who may be finding themselves in a similar situation.

So, I am here for you, if I can help.

HUGS!
D.