Why does radiation tech expose me during treatment setup?

Is It Just Me? I started radiation treatment a week ago. Besides the complete and utter lack of communication regarding what to expect (which is infuriating enough) I'm extremely angry about one thing in particular. The first day, and every day after, there has been a young man who is one of the techs. On the first day he just flipped my gown down so that my breasts were completely exposed. As a victim of SA this was very traumatizing. And every time I go it's the same (and they cover me back up for the radiation so I don't even understand why I'm exposed at first...again, they don't explain anything.) So every day I get to go through this trauma. I can't wait to be done with this because my psyche doesn't need this.